From one end of the empire to another!
The Roman empire encircles the Mediterranean Sea, and beyond that, lay its frontiers. By the early 2nd century the empire was stretching from the Atlantic Ocean to the Black Sea, through the deserts of the Middle East to the Red Sea, and across North Africa.
The “Limes” represents the border line of the Roman Empire at its greatest extent in the 2nd century AD. It stretched over 5,000 km from the Atlantic coast of northern Britain, through Europe to the Black Sea, and from there to the Red Sea and across North Africa to the Atlantic coast. The remains of the Limes today consist of vestiges of built walls, ditches, forts, fortresses, watchtowers and civilian settlements. The two sections of the Limes in Germany, Hadrian’s Wall and the Antonine Wall are now all inscribed on the World Heritage List as the “Frontiers of the Roman Empire”. (Source Unesco)
The Germanic Limes was a line of frontier fortifications that bounded the ancient Roman provinces of Germania Inferior, Germania Superior and Raetia, dividing the Roman Empire and the unsubdued Germanic tribes from the years 83 (under Domitian) to about 260 AD.
The Upper German-Raetian Limes extends to a length of 550 km between the Rhine
in the north-west (near Rheinbrohl) and the Danube in the south-east (near Regensburg). It consisted of about 900 watchtowers, numerous small forts and over 60 large forts for cohorts and alae (Roman allied military units). More a guarded border line than a military defence system, the Limes enabled traffic to be managed, movement of people to be controlled and goods to be traded and taxed.

Rather than expand, secure… the Limes-Emperors (Trajan, Hadrian & Antoninus Pius)
RömerWelt, Rheinbrohl
Having recently moved from London to Frankfurt, I started to explore the Upper Germanic Limes last October. I followed the Limes Road (Limestrasse), a UNESCO World Heritage site encompassing more than 70 towns and villages along the path, with a whole collection of excavation sites, forts, reconstructed towers and museums. Visiting the whole length of the Limes Road will take a few trips. The section covered in this post is from Rheinbrohl (the northern beginning of the Upper Germanic Limes) to Saalburg Roman Fort, north of Frankfurt in Hesse.
This reconstructed watchtower represents the beginning of the Upper Germanic Limes near Rheinbrohl, the so called “caput limitis”. Unfortunately the first stretch of the Limes and the small fort that protected it have been completely destroyed due to gravel extraction. Limes tower 1/1, which was reconstructed in 1973, is situated about 120m southeastern of its original location on the right bank of the river Rhine.
From there the limes ran eastward away from the Rhine in a wide arc across the Rhine valley plain.

WP 1/37 – Reconstructed two-floored Limes Watchtower (not historically correct), near Oberbieber
© Carole Raddato
The watchtowers were located close behind the limes in distinctive positions with lines of sight between each other. WP 1/37 (photo above) was constructed in 1970. Its basement was established in stone building method, its upper floor in framework technology with circulating external gallery. The appearance of the tower does not correspond any longer to today’s state of research. The tower gives however a good idea of its favorable location as point of observation and of the general function of the limes as signal system. Along the limes messages could be passed on from tower to tower with fire, smoke or bugle call up to the next fortlet. (Source: Archäologische Denkmalpflege Koblenz)
From the 2nd century AD, the towers at the limes, first built from wood, were replaced gradually by more rugged stone towers. These usually had a square surface area of 5m by 5m and a height of approximately 10-12m. The entrance was on the first upper floor, which also served as lounge for the 4-8 men strong tower crew. On the ground floor the supplies were probably stored. The guard soldiers in duty stayed on the second upper floor. From the outside gallery they could look out in all directions. The towers were visible far away in the area by their bright colours. (Source and illustration: Archäologische Denkmalpflege Koblenz)
The reconstructed watchtower 1/68 near Hillscheid appears to be the most accurately reconstructed Roman tower along the Limes Germanicus today. It was completed in 1994 and its interior was designed as a museum. Roman auxiliary forts and watchtowers were painted in white with red grout.
Not all watchtowers were fully reconstructed. Some were only partly rebuilt from preserved foundations. This is the case of WP 1/71 (photo above), a square stone tower with 5.60 m on each side and a wall thickness of 100 cm.

WP 2/1 – Reconstructed watchtower 2/1 near Bad Ems, the first and oldest tower constructed at the Limes
© Carole Raddato
The replica tower WP 2/1 near Bad Ems was built in 1874 in honor of Emperor William I, who was a regular spa guest in Bad Ems. It is the first and oldest reconstruction of a tower at the Limes. The design was inspired by images of watchtowers on the Trajan’s Column in Rome and no longer corresponds to the current state of research.

Roman watchtower and beacon on the lower Danube frontier – Detail of plate IV: The watch on the Danube (Scene I) – The Reliefs of Trajan’s Column by Conrad Cichorius (wikipedia)
For a long time, only a strip cleared through the woods existed on the Limes, a patrol track monitored by wooden towers. Under Hadrian, the patrol track along the border was additionally secured with a continuous palisade fence: the Limes line was closed (source: The Roman Limes in Europe, Friedrich Lüth). The preserved wall lines and reconstructed palisade you see on the picture below demonstrates this.
While there is no reconstructed milecastle on Hadrian’s Wall (Rome’s Northern Frontier), you can see an authentic reconstruction of a fortlet at Pohl. It has been reconstructed close to its original position, together with a typical watchtower based on recent research.
This reconstructed fort is designed as an open air museum with lots of exhibitions and events. It also functions as an information center as well as a central starting point for many activities in the region.
Today, the Holzhausen fort, now located deep down the forest, is amongst the very best preserved fort along the Limes. It was erected under Emperor Commodus (180-192 AD) and survived until the abandonment of the Limes in the years 260 AD. The Cohort II Treverorum served as the fort’s garrison. The name of the 500-man unit has been handed through several building inscriptions.
Several stone foundations from the headquarters building (principia) are recognisable in the interior, particularly the semi-circular apsis of the standard’s shrine. The campaign symbols of the troops were stored here, and one also paid tribute to the emperor (photo below).

The Aides, or shrine, at the centre of the office block on the far side of the headquarters building, where the regimental standards were preserved and kept on display, Saalburg Roman Fort
© Carole Raddato
The best representation of the Limes is to be found in Saalburg. There, archaeologists working in the late 1800s unearthed the foundations of a Roman fort and set about restoring it to its former glory.

The Porta Praetoria (Main Gate) with statue of Antoninus Pius and inscription referring to Wilhelm II., Saalburg Roman Fort
© Carole Raddato
Saalburg is a Cohort fort located just North of Frankfurt and is the most completely reconstructed Roman fort in Germany.
After 83 A.D. a small wooden castle was built on the site where Saalburg Fort stands today. By 135 AD, the wooden fort was converted into a cohort fort with a crew of about 600 men, protected by a wooden palisade and stone watchtowers.
Behind the entry gate to the right lies the granary (latin horreum) which now serves as a museum. Between the two doors we see the bust of the founder of the Saalburg Museum, Professor Louis Jacobi.

The reconstructed horreum (grain store – granary) now houses the museum, Saalburg Roman Fort
© Carole Raddato
Numerous photos of the Saalburg fort and the museum can be viewed here.
The varied landscapes through which the Limes line passes, and the fascinating Roman heritage offer great walking and cycling opportunities. Much of the line of the Limes is followed by the Limestrasse road which links many fine traditional towns and villages and there are many signposted footpaths and cycleways.
I cannot wait to explore the Limes again next week (see itinerary map here)
Further photos of the Limes Germanicus can be viewed from my image collection on Flickr.
Links and further reading:
Frontiers of the Roman Empire (youtube channel)
