Frontiers of the Roman Empire – The Lower German Limes (Germany)

Description

The Lower German Limes is a distinctive part of the frontiers of the Roman Empire, which protected this extensive empire over the three continents of Africa, Asia and Europe. Three frontier sections have already been jointly inscribed on the World Heritage List, as component parts of the property Frontiers of the Roman Empire (430ter: Hadrian’s Wall 1987, Upper German-Raetian Limes 2005, Antonine Wall 2008). The Lower German Limes will be nominated as a single, distinct (serial) property, following the nomination strategy for the Frontiers of the Roman Empire, written in 2017 by the States Parties involved in the proposed nomination of the frontiers in Europe. The World Heritage Committee has taken note of this nomination strategy and the underlying thematic study at its 41st session at Kraków (41 COM 8B.50).

The Lower German Limes constitutes the north-eastern boundary of the Roman province of Germania Inferior (Lower Germany), running for 400 km along the river Rhine, from the spurs of the Rhenish Massif south of Bonn in Germany to the North Sea coast in the Netherlands. The military infrastructure was established in the last decades BC and existed, after a temporary breakdown in the late 3rd century, until the disintegration of the Western Roman Empire in the early 5th century AD.

The highly dynamic character of the Lower Rhine, particularly in its extensive delta in the Netherlands, made a strong appeal to the ingenuity of the Roman military engineers. A groyne and canals were designed to enhance its navigability, and quays and landing platforms to facilitate its use for logistical purposes. Designs of forts and roads were adapted to cope with the whimsical behaviour of the river. These peculiarities are demonstrated by outstanding remains of timber and other organic materials, which are excellently preserved by the wetland conditions of the Lower Rhineland.

The Roman military infrastructure along the Rhine was established as a springboard for the conquest of Germanic territories across the river. Once this ambition had failed, the left river bank was converted into a fortified frontier – the first European river frontier to develop. The Lower German Limes also provides a fine example of the development of an urban infrastructure in a region without central places, illustrating the spread of Roman administrative and architectural traditions.

Description of the component part(s)

The nominated property consists of some sixty component sites. The section starts on the North Sea coast near Katwijk aan Zee and ends at Remagen, where the Upper German-Raetian Limes (inscribed 2005) starts on the opposite river bank. Due to migration of the Rhine channels in and after the Roman period some sites are no longer situated on the active river channel, while a few have been washed away. Yet, the close relationship between military posts and the river is still evident in many places.

The military fortifications consist of large legionary bases and temporary camps, smaller forts for auxiliary units and some watchtowers. The wetland character of the frontier section is clearly expressed by a dug canal, a fleet base, a bridgehead, and harbour installations at many fort sites; it is also illustrated by sunken ships and by timber revetments and other constructions associated with the military road. Industrial sites, military sanctuaries and an aqueduct testify of the impact of the varied military needs on the landscape, while the governor’s palace, fortified towns and settlements outside forts bear witness of the interweaving of the military and civilian worlds.

The component sites have been selected on account of their contribution to the Outstanding Universal Value of the Lower German Limes, of their authenticity and integrity, and of the feasibility of management and long-term protection.

List of component sites in Germany

LGG001 | Kleve | Kleve | Keeken

Coordinates: 6,077456 / 51.841072

Vexillation fortress / fort | Date: 0 - 400

Integrity: Approximately 50% of the vexillation fortress or fort are known by aerial reconnaissance. Two ditches on the north, west and south side are known and preserved in an agricultural area. The known two corners form the west and rear side of the installation with xx m. The two parallel ditches and the unusual large size are indicating a vexillation fortress or an unusual large auxiliary fort.  Further research about its extend to the east (towards the former banks of the river Rhine) and about possible internal structures is needed. A very good preservation in the prospective eastern part is very likely.   

Authenticity: Its position south of the Waal-Rhine bifurcation is still recognisable in the landscape. The existence of an important temporary or permanent base of the roman army at this strategic position demonstrates the importance of the river network for the roman army.  

LGG002 | Kleve | Kleve | Reichswald

Germania Inferior | Coordinates: 6,093 / 51,7885

Limes road | Date: 0 - 400

Integrity: Original remains of the Limes road leading from Kalkar towards Nijmegen with ditches and road embankment are attested by LiDAR scan and by excavation trenches in a forest near Kleve. The preserved road embankment is still visible in the forest.

Authenticity: The road embankment is still visible in the forest area. The site is together with the limes road near the fort Kalkar/Burginatium one of the best-preserved road embankment of the limes road along the German part of the LGL. As the main road between Xanten and Nijmegen it is an important testimony for the artificial network connecting the main military and civil centres in the middle part of the LGL.

LGG003 | Bedburg-Hau | Till | Kapitelshof/Steincheshof

Coordinates: 6,24 / 51,776

Ensemble of a legionary fortress, auxiliary fort, a vexillation fortress and several temporary camps| Date: ca. 40 - 150

Integrity: The cluster of roman military installations around the Kapitelshof and Steinchesof lies in an agricultural area. The extent and layout of the installations are attested by large-scale geophysical surveys and aerial reconnaisance; smaller excavations trenches showed excellent preservation of archaeological layers with partly wetland conditions. The extent of the fort is still visible by its well-preserved archeological layers, which form a 0.5m high platform above ground.

Authenticity: The extent of the legionary fortress, the auxiliary fort, the vexillation camp and the temporary camps and their commanding position in the landscape is still recognisable. It is one of the major concentrations of installations of the roman army along the LGL.

LGG004 | Kalkar | Kalkar | Kalkarberg

Coordinates: 6,285 / 51,7288

Military sanctuary | Date: -20 - 400

Integrity: The site of the sanctuary of the Germanic war goodess Vagdavercustis is well known by geophysical survey, aerial photography and modern excavation. Significant parts inside the temenos are untouched and excavation showed very well preservation conditions. The site is not overbuilt and it is used as agricultural farmland.

Authenticity: Hugh amounts of finds of military equipment and epigraphic evidence for the worship of Vagdavercustis by roman soldiers are demonstrating a rarely attested aspect of roman frontiers: the worship of indigenous gods or goddesses by the roman army. The commanding view from the sanctuary into the Rhine valley and its landmark position is still recognisable.

LGG005 | Kalkar | Kalkar | Altkalkar

Burginatium | Coordinates: 6,321 / 51,7141

Fort, vicus, limes road | Date: -20 - 400

Integrity: The cavalry fort of Burginatium is one of the best preserved roman forts along the LGL. Fort, vicus and limes road are well known by geophysical surveys and aerial reconnaissance. A modern road (B57) is running over its south western corner, without significant impact on the archeological layers below. Smaller excavation trenches along the B57 showed well-preserved layers of the fort and its vicus. The embankment of the limes road is still visible for ca. 200 m in the agricultural area. A trial trench and core samplings revealed massive layers of organic material in front of the fort in the silted up former Rhine bed. 

Authenticity: The well attested ground plan of the cavalary fort and rich epigraphical sources of cavalry units stationed at Burginatium make it an important element to demonstrate the structure of cavalry forts and the daily life of the elite units of the auxiliary troups of the LGL. The good accessibility of the site is providing an important understanding of the sitting of fort, vicus and limes road in a typical riverine landscape.       

LGG006 | Uedem | Uedem | Hochwald

Coordinates: 6,3592 / 51,6907

Temporary camps | Date: 20 - 200

Integrity: The earthworks/ramparts of 13 temporary camps are well preserved in a forest area. All camps are known in their full extent by the good preservation of the ramparts and gates in form of claviculae. The camps are concentrated in a coherent and complete cluster.

Authenticity: The cluster reflects the temporary use of this place as a manoeuvre area for the roman army and demonstrates the important aspect of training the troops. The well visible ramparts and gates can still be recognized and seen as a manifestation of the roman military discipline.

LGG007 | Wesel | Flüren | Flüren

Coordinates: 6,5617 / 51,6838

Temporary camps | Date: 20 - 200

Integrity: The earthworks/ramparts of four temporary camps are well preserved in a forest area. All camps are known in their full extent by the good preservation of the ramparts and gates in form of claviculae.

Authenticity: The cluster reflects the temporary use of this place as a manoeuvre area for the roman army and demonstrates the important aspect of training the troops. The well visible ramparts and gates can still be recognized as a manifestation of the roman military discipline. The position of the camps on the right side of the Rhine demonstrates the ability and aim of the roman army training the troops in crossing the river Rhine, as mentioned by the historian Cassius Dio.

LGG008 | Xanten | Xanten | CUT area

Coordinates: 6,4447 / 51,6668

Limes road | Date: -20 – 100

Integrity: The limes road is well attested by aerial reconnaissance and excavations in the area of the later roman town Colonia Ulpia Traiana. With the foundation of the town ca. 100 AD, the course of the road system was changed. Still large parts of the former limes road are preserved under the structures of the civil town of CUT.

Authenticity: The limes road under the later town of CUT represents the important strategic line of the transport corridor of the LGL.

LGG009| Xanten | Xanten | CUT area

“South quarter” | Coordinates: 6.444356 / 51.662817

Defensive structure | Date: 250 - 300

Integrity: The defensive structure of a stone wall with two gates in the south west corner of the CUT was recently detected by geophysical survey and attested by excavation. It is presumed to be a 3^rd century fortification in the still existing civil town of CUT.

Authenticity: The fortification reflects the strong relationship between civil settlements and military activity along the LGL.

LGG010 | Xanten | Xanten | CUT area

“Tricensima” | Coordinates: 6,4425 / 51,6664

Late roman fortress | Date: 300 - 400

Integrity: The late roman fortress in the centre of the former CUT is known by its full extend through excavations. Two U-shaped ditches and a stone rampart with projecting round-towers show the typical layout of a late roman fortification. Its interior encompasses the nine central insulae of the former civil town. It seems most likely that the late roman fortress can be identified with “Tricensima”, the late roman successor of the legionary fortress of the 30^th legion at Vetera II providing enough space to include also areas for civil settlement.

Authenticity: The late roman fortress demonstrates the development of the late roman defence system with its typical massive defensive structures. With its size of 16 ha it is the largest late roman fortification along the LGL. Its orientation to the layout of the former CUT demonstrates also the close relation between military and civil live along the roman frontier.

LGG011 | Xanten | Xanten | Vetera I

Coordinates: 6,4705 / 51,6419

Legionary fortress | Date: -20 - 70

Integrity: The legionary fortress of Vetera I is known by narrow excavation trenches, aerial reconnaissance and large scale geophysical survey. The different phases are largely preserved in agricultural area and have never been overbuilt. The wooden-earthen amphitheatre is still fully preserved and its rampart is still several meters high; the remains of the later legionary fortress of Vetera II, some few hundred meters to the east, are re-deposited by the later course of the Rhine and will be integrated in the buffer zone of Vetera I.

Authenticity: The topographical position of the fortress at the Fürstenberg is described by the roman historian Tacitus as one “part of the fortress laying on a gentle slope, (and one) part could be approached on level ground”. This authentically view can still be recognised in the landscape today.

LGG012 | Alpen | Alpen | Boenninghardt

Coordinates: 6,4949 / 51,5835

Temporary camp | Date: -20 - 200

Integrity: The ditch and two gates with tituli of an unusal large temporary camp are known by aerial reconnaissance and trail trenches. The site is largely preserved in agricultural area.

Authenticity: The extent of the site and its commanding view into the Rhine valley is still recognisable. As one of the largest temporary camps it reflects the military activity of large army groups of the provincial army marching along the LGL.

LGG013 | Alpen | Alpen | Drüpt

Coordinates: 6,5464 / 51,5868

Fort, temporary camps | Date: 20 - 200

Integrity: The auxiliary fort has been discovered recently by large scale geophysical survey and in combination with aerial reconnaissance its interior layout is well attested. Its major part with the central buildings is preserved in agricultural area. The front of the fort is re-deposited by a later Rhine course. An excellent preservation of organic materials of the eroded front part is therefore very likely and will be integrated in the buffer zone. Next to the fort, two large temporary camps are known.

Authenticity: The extent of the fort and its commanding position on the former Rhine course is still recognisable. The fort closes a major gap between the legionary fortress of Vetera and the cavalry forts of Moers-Asberg/Krefeld-Gellep and is therefore of high importance for the understanding of the military organisation of the LGL in its central part. The large temporary camps underline the important strategic position of this military base.

LGG014 | Moers | Moers | Asberg

Asciburgium | Coordinates: 6,6699 / 51,4317

Fort | Date: -20 – 100; burgus | date: 360 - 400

Integrity: The fort is partly overbuilt by sinlge-family houses but still large areas show good preservation conditions. At least five wooden building phases are well preserved. In Roman times, the fort was located directly next to the Rhine. Some organic deposits from layers in front of the fort are remaining. Appropriate for forts next to the river, a place to land with flatboats has been detected.

Authenticity: The fort is an important testimony to the early stationing of auxiliaries at the river Rhine. Thorough research concerning dated finds yielded that there were legionaries already at the time of Emperor Augustus.

LGG015 | Duisburg | Duisburg | Werthausen

Coordinates: 6,7113 / 51,4221

Fortlet | Date: 20 - 200

Integrity: The fortlet has been excavated in the late 19^th and early 20^th century with small trenches. Today parts of the underlying remains are overbuilt, other parts are covered by lawns and well protected.

Authenticity: It used to be on the right bank of the Rhine. This suggests that the Rhine was not a rigid border, but his entire broad riverbed was at least partially under Roman influence. Its function was probably the monitoring of the Rhine, which meandered at this point strong and made at Werthausen a wide riverbed that was easy to cross at low tide.

LGG016 | Krefeld | Krefeld | Gellep

Gelduba | Coordinates: 6,6824 / 51,3333

Fort | Date: 70 - 430

Integrity: The Roman fort of Gelduba is largely preserved in agricultural area. The archaeological layers of the fort are still preserved up to 2 m. The front of the 2nd/3th century fort has been destroyed during the extention of a port. Exceptional is the unusual good preservation of remains of 4th and 5th century activities.

Authenticity: The extent of the fort and its commanding position between the former Rhine course still recognisable. The area has already before the establishment of the fort been an important place of events of the Batavian revolt. Unique findings like buried horses tell about the battle.

LGG017 | Neuss | Neuss | Koenenlager

Novaesium | Coordinates: 6,7244 / 51,1823

Legionary fortress | Date: 40 - 100; fort |date: 100 - 300

Integrity: The legionary fortress and its succeeding auxiliary fort are situated in urban area. The layout of the fortress is well known due to the nearly complete investigation by narrow trenches during the end of the 19^th century. Despite today's overbuilding, the vast majority of the fortress has been preserved in good conditions in green spaces and under roads and paths, particularly because during the excavation not the entire surface has been touched.

Authenticity: The layout of the fortress and the fort is partly still identical with the modern street pattern. The main road (via principalis) is still the major modern road in this area. For the first time, the epoch-making excavations provided the largely complete layout of a legionary fortress, which still determines international literature. Named after the main excavator as “Koenenlager” the fortress is still today seen as the iconic example of an typical roman legionary fortress.

LGG018 | Neuss | Neuss | Reckberg

Coordinates: 6,7676 / 51,175

Watchtower, fortlet | Date: 40 - 300

Integrity: The two buildings are preserved in forest area and have partly been excavated in the 19th century with small trenches.

Authenticity: Situated on a small hill and in a commanding postion and positioned next to the limes road the fortlet has a good view over the landscape, the river and the limes road. It makes the site an important place for the understanding of the surveying task of the roman army.

LGG019 | Monheim | Monheim | Haus Bürgel

Coordinates: 6,8729 / 51,1294

Fort | Date: ca. 300 - 400

Integrity: Large parts of the walls of the late Roman fort are well preserved and remaining up to 4 m high integrated in younger buildings. Together with some excavations, the layout of the fort is well known. The complex is situated in agricultural area in a natural reserved area today on the right side of the Rhine which changed its course in 1374.

Authenticity: The medieval fortification with the integrated exceptional high remaining Roman walls host a museum and are explained with an archaeological path. As situated in a rural region, the view to Haus Bürgel is unimpeded and gives an impression to the prospect of the fort.

LGG020 | Dormagen | Dormagen | Dormagen

Durnomagus | Coordinates: 6,8404 / 51,0927

Fort | Date: 100 - 400

Integrity: Above ground there is no sign of the auxiliary fort. However, during the excavations it was possible to find well-preserved substance in the earth and to study about 28% of the fortified area. At least nearly three quarters are preserved in urban area.

Authenticity: The commanding position above the former Rhine course is still recognisable and the main road (via principalis) is still identical with a modern road. During the excavation in the 1960s it succeeded for the first time to excavate urine-pits in the barracks which prove the presence of horses in the barracks. This discovery is essential for the interpretation of cavalry forts and the daily life of soldiers and their horses.

LGG021 | Köln | Köln | Deutz

Divitia | Coordinates: 6,9694 / 50,9378

Bridgehead fort| Date: 300 - 400

Integrity: The bridgehead fort on the right side of the Rhine opposite to the CCAA is partly preserved in urban area. Large buildings like a monastery overbuild some areas. The preservation with upstanding walls at different locations is excellent.

Authenticity: Located directly at the riverside, parts of the remaining walls are integrated in open public recreation area. The commanding position opposite to the roman town of Cologne is still recognisable as well as the position of the former late Roman bridge.

LGG022 | Köln | Köln | Praetorium

Coordinates: 6,959 / 50,9385

Governor's palace | Date: 20 - 400

Integrity: Excavated after the extensive destruction of the WW II, the headquarter of the governor is largely preserved in the urban area. The preservation of the building with upstanding walls is excellent and the different building phases are recognisable.

Authenticity: Preserved remains of a governor´s palace are very rare. It served as the headquarter of the roman army of Lower Germany. The main part of the building is integrated in a subterranean museum and will be part of the future widespread archaeological park. The function of the Roman building continues in this place as the modern town hall is above.

LGG023 | Köln | Köln | Alteburg

Coordinates: 6,9766 / 50,905

Fort (fleet base) | Date: 20 - 250

Integrity: The fleet base of the classis Germanica is partly preserved in an urban district with large garden areas. Specific excavations prove excellent preservation conditions and recent geophysical surveys made parts of the building structure in the centre of the fort visualized.

Authenticity: The position of the fleetbase and its commanding position at the Rhine bank is recognisable. In it´s function of monitoring the Rhine, it operates on the entire border of the Lower German Limes.

LGG024 | Alfter/Bornheim | Alfter/Bornheim | Kottenforst-north

Coordinates: 6,9751 / 50,7201

Temporary camps | Date: 20 - 200

Integrity: The earthworks/ramparts of 12 temporary camps are well preserved in a forest area. All camps are known in their full extent by the good preservation of the ramparts and gates in form of claviculae. The camps are concentrated in four different and complete cluster.

Authenticity: The cluster reflect the temporary use of this area as a manoeuvre area for the roman army and demonstrates the important aspect of training the troops. The well visible ramparts and gates can still be recognized and seen as a manifestation of the roman military discipline.

LGG025 | Bonn | Bonn | Bonn

Bonna | Coordinates: 7,0996 / 50,745

Legionary fortress | Date: 20 - 400

Integrity: Since the 20 century the area of the legionary fortress started to be overbuilt by functional buildings and residential houses. Excavations have been made since the early 19^th century but still 83 % of the legionary fortress is well preserved and untouched.

Authenticity: This site is on of the most significant military positions along the Roman frontier and it is one of the largest legionary fortresses. Its layout and the roman street pattern is still identical with the modern street pattern. The elevated flood-proof location above the Rhine is still easy to understand. Directly in front of it the harbor is situated which will be incorporated in the buffer zone.

LGG026 | Bonn | Bonn | Kottenforst-south

Coordinates: 7,0927 / 50,6695

Temporary camps | Date: 20 - 200

Integrity: The earthworks/ramparts of 10 temporary camps are well preserved in a forest area. All camps are known in their full extent by the good preservation of the ramparts and gates in form of claviculae. In contrast to the other concentrations of camps, these camps are dispersed over a large area.

Authenticity: The cluster reflect the temporary use of this area as a manoeuvre area for the roman army and demonstrates the important aspect of training the troops. The well visible ramparts and gates can still be recognized and seen as a manifestation of the roman military discipline.

LGG027 | Bad Münstereifel | Bad Münstereifel | Iversheim

Coordinates: 6,7739 / 50,5882

Industrial complex (lime kilns, 30th Legion) | Date: 50 - 300

Integrity: Well preserved remains of a series of six lime kilns integrated in a working building have been excavated and different building phases proved. In addition to the kilns themselves and the working building, further spatial structures for storage, protection and residence have been discovered. Some walls probably for residence are multicolored painted.

Authenticity: By inscriptions, there is no doubt that the complex was operated by the 30^th legion of Xanten. Most of the original lime kilns are integrated in a small museum and one of them has been rebuilt after the excavation and an experimental lime burning test has been carried out after the excavation. About 300 m to the north there is another battery of lime kilns known by inscriptions which will be included into the buffer zone.

LGG028 | Königswinter | Königswinter | Drachenfels

Coordinates: 7,2054 / 50,6665

Industrial complex (stone quarry) | Date: 20 - 300

Integrity: At the Drachenfels the original remains of Roman stone quarrying are still preserved at different locations. The Drachenfels Trachyte, which was used for buildings and inscriptions throughout Lower Germany, was quarried there.

Authenticity: Situated in a large natural reserve different locations where remains of the Roman stone quarrying techniques are still visible. As well as the original remains the location of the quarry next to the river Rhine is still in situ and a natural landing platform is attested.

LGG029 | Remagen | Remagen | Remagen/Rigomagus

Coordinates: 7,2276 / 50,5797

Fort | Date: -6 - 400

Integrity: The fort is located in the centre area of the old town city and mainly overbuilt. Recent excavations show that the archaeological structures underneath the modern buildings are mainly well preserved. Parts of the walls of the stone rampart are still upstanding and protected by modern walls.

Authenticity: The preservation of parts of the principia is excellent. The remains are integrated in a small museum. The main road (via principalis) is still identical with a modern road.

Justification of Outstanding Universal Value

Criterion (ii): The Lower German Limes formed part of the frontiers of the Western Roman Empire throughout its existence. As such it reflects the development of Roman military and associated civilian infrastructure from its beginnings in the last decades BC until the mid-5th century AD. The needs of the Empire moulded the regional landscapes and societies, as evidenced by water management works, industrial exploitation of natural resources, road construction and the imposition of a complex military and urban infrastructure. On the other hand the cultural and natural characteristics of the region shaped the outward appearance of the Empire, as testified by adapted designs of military settlements and buildings, and of ships and roads. Ultimately, the frontier served as a starting point for the Early Medieval civil and religious infrastructure, which is at the basis of the present-day society.

Criterion (iii): The remains of the Lower German Limes testify to the adaptive strategies of the Roman Empire in a marginal and very dynamic river landscape, to deal with the threats posed by the fragmented Germanic communities across the Rhine. As such it is an exceptional testimony to the innovative responses of a great empire to secure its territories against external groups which it found impossible to control by diplomacy.

Criterion (iv): The Lower German Limes exhibits unique testimonies of water management strategies and constructions employed by the military command of the Roman Empire. These are exemplified by a dug canal, heavy quays and landing platforms, adapted fort designs and road sections protected by timber revetments. Buried riverine rubbish deposits constitute veritable treasure-chests of organic materials and artefacts bearing unique information on frontier life and on vanished traditions such as notably that of river boat building.

Statements of authenticity and/or integrity

Authenticity

Virtually all of the component sites are underground and remain largely unexcavated. They are the original remains and as such exhibit complete authenticity. A few parts have been excavated and have then been properly conserved and presented in situ. All these elements retain their authenticity. The ex situ finds, although not part of the nomination, have been documented, conserved, and archived in a proper way and are used to help explain the properties values and as such strengthen the OUV.

Because the in situ remains of the Lower German Limes are almost all below ground and hence invisible, their value needs some form of translation in order to be understandable for the general public. This need has led to a number of innovative projects to convey these values. Several sites are presented symbolically by expressing their boundaries on the surface, after raising it with a protective layer of soil. In this way, the authenticity and integrity of the underground remains as well as the setting and integrity of the surroundings are protected. Such symbolic representations are well suited to create a minimum level of public experience of the Limes without resorting to reconstruction in its classical form.

The authenticity of the nominated property is ascertained in that it is truthfully and credibly expressed through incorporation of the full variety of Roman military and associated civilian facilities. In form and design as well as function all elements from the subsequent chronological stages of military deployment are represented at their original location. In many areas, organic remains are demonstrably or plausibly present, so that here too the authenticity is credibly expressed in materials and substance.

Integrity

The Lower German Limes is a river frontier. Although the military installations were connected by a land road, the river was explicitly part of the military infrastructure. Until recently, the Rhine was still meandering, which explains why certain sections of the Roman Rhine have not survived to the present day; in some parts the Rhine bed has already migrated during the Roman Period. Nevertheless, geological and archaeological research has revealed that the Roman river system is largely extant, along with most of the military infrastructure that is preserved below ground. Due to this location and to the high groundwater table many organic remains have been preserved in excellent condition. This provides for a very high level of archaeological integrity, with finds and features preserved in their original context in the soil matrix.

The remarkable standard of survival is not invalidated by evidence that original layers have occasionally been washed out and re-deposited by the river, both during and after the existence of the frontier. This is considered to be a normal feature of any river frontier. The Lower German Limes does not have many standing remains preserved above ground. Some remains have been brought to light during archaeological excavations or other works, but in general visible stone-built elements have been torn down and reused in the Middle Ages, as may be expected in a region lacking natural stone resources in most parts. Reused Roman stone can be traced in many Early and Late Medieval structures, adding another layer to the history of the Lower Rhine region. Architectural elements of stone as well as foundations have been preserved below ground, imparting additional significance to the exceptional organic remains.

In selecting component sites for the nomination care has been taken to include the full variety of elements that is typical for this part of the Roman frontiers, both in a chronological sense and in covering the full range of variability. In that way, the wholeness of the property is adequately represented and its intactness is further supported by the fact that only sites with substantial archaeological integrity have been selected.

Justification of the selection of the component part(s) in relation to the future nomination as a whole

The selection of component sites is in keeping with the principles agreed upon in 2004 by the States Parties involved in the anticipated extension of the Frontiers of the Roman Empire World Heritage property: to select the frontier lines of the 2nd century AD, and military installation of different (Roman) periods which are on that line, and to include military installations, road infrastructure, artificial barriers and immediately associated civil structures (Koblenz Declaration, attached to ref. 430bis). This declaration served as a point of departure for the 2017 thematic study.

The site selection of the Lower German Limes reflects its full chronological and functional variety. It includes military fortifications from all (Roman) periods, ranging from watchtowers to large legionary bases, and the land and riverine infrastructure connecting them. Various features exemplify the wetland character of this river frontier section. The needs of the military are illustrated by industrial sites, military sanctuaries and an aqueduct, while the provincial governor’s palace, fortified small towns and settlements outside forts demonstrate the dovetailing of the military and civilian worlds in the frontier landscape.

Comparison with other similar properties

In the context of the preparation of a number of proposals for extensions from several States Parties to the serial transnational property Frontiers of the Roman Empire, a thematic study has been undertaken by involved States Parties in Europe on the basis of which an overall nomination strategy has been developed for the whole Roman frontiers and a detailed strategy for the European section of the Roman frontier. The World Heritage Committee has taken note of this nomination strategy at its 41st session at Kraków (41 COM 8B.50).

In the thematic study and nomination strategy five discrete groups of frontiers have been distinguished (names of Roman provinces in italics):

• The desert frontier of Africa, Egypt, Arabia and southern Syria served to protect long distance trade routes crossing the desert and to control the nomadic tribes of the region. Within this group there is some regional variety, with for instance some artificial barriers and mountainous sections in Africa and a deviating positioning of military installations in Egypt.
• The Parthian frontier of northern Syria and Cappadocia (Turkey) combines a river and a mountain frontier and served as the military backbone for the Roman claims on Armenia and Mesopotamia, which were disputed by the Parthian Empire.
• The river frontier of the Rhine and Danube separated the Roman Empire from areas which it considered as ‘barbaric’ and outreached its powers or interests. Varying natural conditions and threats are reflected in regional differences in size, design and spacing of military installations.
• The artificial barriers of Hadrian’s Wall, the Antonine Wall, the Upper German-Raetian Limes – constituting the already inscribed World Heritage property (ref. 430ter) – were built where no convenient rivers were available to constitute a frontier line.
• The mixed frontier of the Roman province of Dacia (Romania) provides an unparalleled mixture of military responses to natural and political conditions. It combines sections of mountain and river frontiers with long and short linear barriers.

Further, it was argued that the river frontiers of Rhine and Danube have different characteristics justifying nomination as distinct properties. The Danube frontier outstandingly demonstrates the evolution of Roman military responses to external pressure and has many standing remains illustrating the longest survival of a river frontier. The Lower German Limes (Rhine) represents the very beginning of the linear perimeter defence of the Roman Empire and is a wetland frontier.

Thus, although part of a coherent frontier system spanning three continents, the Lower German Limes has distinct characteristics emanating from innovative responses to local natural and political conditions.