After I returned, I was able to consult an excellent book on the subject: 'Tripolitania' by David J. Mattingly (son of the famous Harold Mattingly) which provided more information on these southern Limes.
Tunisia, along with parts of Libya, occupies roughly what was once the Roman province of Africa Proconsularis. It can be divided into two halves. The north is green and fertile and mountainous to the east, watered by weather systems from the Mediterranean. To the south is desert. The changeover point is the east-west, Cherb range of hills/mountains (see map). South of those mountains are the 'Chotts'. These are vast salt lakes or pans that stretch from Algeria, across Tunisia almost to Gabes on the coast. The area of the largest, Chott el Jerid', is 7000 sq. km. They mostly resemble vast areas of flat, wet sand. There is more open water in the winter when the evaporation is lowest.
Although the Chotts are sometimes passable with caution, they would have been a formidable barrier in ancient times. As well as the Cherb mountains to the north, there is a range to the south of Chott el Fejej called Jebel Tebaga, and a north-south range, which includes Jebel Demmer and the Matmata range, that separates the coast from the desert. To the west is the great sand sea, the Grand Erg Oriental.
The collective name for the Roman walls, ditches, roads and forts in this area and stretching down into Libya, is the Limes Tripolitanus. The function of these devices was not to present an impassable barrier to movement but to control movement between the desert and the populated and fertile areas including the coast as well as creating a hegemony over tribes living on the margins of the desert. Many of these tribes were nomadic, travelling from oasis to oasis with their herds most of the year. But at the end of summer they would transfer their herds to the Chott el-Djerid area, where they worked gathering olives.
This is a close-up map of central Tunisia, at the northern end of the Limes Tripolitanus
The numbers refer to the places visited, which are described in individual posts below.
1. The walls at Bir Oum Ali
2. The Fort Benia Guedah Ceder
3. Anonymous desert lookout tower
4. The walls at Degache
The walls at Bir Oum AliThe Cherb range of mountains provide a barrier between the fertile north of Tunisia and the desert south and in Roman times also separated the territory of the Capsitani and the Nybgenii. To control movement between north and south, the Romans built walls, known as Clausurae (meaning 'the fortification in a defile), in passes and wadis at several places (but not continuously). The best preserved are at Bir Oum Ali, on the road from Gafsa to Kebili. The fact that this is a modern road means that much of the wall and the gateway that allowed passage through the walls have been removed. However, there are remarkably preserved sections of wall to the north and south of the road as we discovered.
The wall stands up to 6m in places and is approximately 1.5m wide. It consists of two faces of small neat masonry with a rubble and mortar fill. The 'bricks' for the masonry would have been available all around.
There are up to 9 other remains of clausurae in the Cherb range, dating to the beginning of the second century. Rather than being defensive, it is believed that the walls and gates controlled movement between the pastoral desert and the settled agricultural north.
The Fort Benia Guedah CederBetween the range of mountains called Jebel Tebaga and the Matmata Hills is what is known at the 'Tebaga Gap'. It provides an easy passage from the desert to the coast. Even in modern times it has had strategic importance. In 1943 it was part of the Mareth Line, defended by Germans and Italians against the Allies. In March 1943 the Tebaga Gap was breached by New Zealand and British forces.
In Roman times, the gap was closed by more clausurae, about which more below. In the middle of the gap is a well-preserved fort, called Benia Guedah Ceder. Like most ancient remains in Tunisia, it was first discovered (from a European point of view) during the French colonial period. Some excavation and possibly some reconstruction has taken place.
The style of the fort indicates fourth century, but pottery shards seem to indicate an earlier date, possibly third century. The size is 60 x 40m. The walls are built of good quality ashlar masonry, 0.60 - 0.80m thick. There are square bastions projecting at the south, east and west corners.
The Jebel Tebaga clausura has been recognized as a 17km linear earthwork from Gebel Tebaga to the foothills of the Gebel Melab. This consisted of walls on the scarps of the Jebels and ditch and bank across the valley floor. The maps in 'Tripolitania' seems to show this clausura passing adjacent to the fort. On our visit, this was not immediately obvious. We did pass through a couple ditches in our 4x4's but they appear to date from WWII. Clearly the wall in the foreground of the picture above is not part of a clausura, but an external building, possibly a Byzantine addition.
There is a sister fort close to the same clausura called Benia bel Recheb. There are also several forts stretching to the south along the Limes Tripolitanus.
Anonymous desert watch towerInterspersed between the main forts of the Limes were manned lookout towers. These had the job of watching out for any unusual movements and reporting to the nearest fort by signal or horse.
Of course, the location of the remains of these towers is not always obvious. However, the skilled archaeologist will always ask at the local pizza joint.
As can be seen from the next picture, this 'tower' resembles more a pile of stones. However, the evidence is there to be found.
There is evidence of a midden (rubbish heap) outside of the presumed entrance to the tower. Also a short distance away, there seems to be evidence of a few dwellings.
The walls of DegacheIf the Tebaga gap channelled movement on the east side of the country, then there was a gap on the west side which must have provided easy passage south to north. This gap is that between the Chott el Jerid and the Chott el Gharsa and to the west of the eastern tip of the Cherb range. The main town in this gap today is Tozeur. It sits around a large oasis which today has growing in it over 200,000 date palms. The Roman town was called Tusuros. In the medieval period it grew rich by acting as the terminus for trans-Saharan caravans.
The area must have been protected during the period of Roman rule, but it doesn't appear in any accounts of the Limes and no reports from the French colonial period appear to have been made (well, I haven't scoured the archives of the Bibliothèque nationale, but as far as I know). We were told of some walls at Degache, so we set off to investigate.
Degache is just a few kilometres to the northeast of Tozeur. It has its own oasis. The nearby Roman town was called Thegis.
In the middle of the oasis we found this rather impressive wall.
Typically Roman pottery shards were found in the vicinity. Our resident archaeologist was satisfied that this is indeed a Roman wall. Whether it was part of the Limes or was built for some other purpose is difficult to say.
Well, that is the end of this little archaeological adventure. I hope has been of some interest.