At the request of the German Archaeological Institute in Damascus (Syria), the Geodetic Institute of the Technical University Munich surveyed the remains of a late Roman settlement that included a castellum. The fortified settlement, Al Hallul, was part of the eastern border fortifications, the Strata Diocletiana, built about 300 AD by the Roman emperor Diocletian.
Al Hallul lies about 50km south of the Euphrates settlement Al Mansura, on the northwest slope of a small hill, the only high ground in the area. The summit of the hill is 334m above MSL. The town’s fortified walls enclosed an area of about 400m x 220m, the castellum at its centre measures 40m x 40m. A cistern system lies some 120m to the north of the town, and the ruins of two villas built around 600 AD are about 350m to the west.
Over the centuries, earthquakes, wind, and sun have changed the small town into a hill. Destruction is also caused by bedouins who use it as a quarry for stones to build new houses, despite a prohibition by Syria’s Department of Antiquities. Our survey was necessary to complete the records of fortifications on the former frontier.
We used Leica total stations for the survey. First of all, we had to establish a grid of ten ground controls, mark them with steel pipes, and triangulate them. From these ground controls we then measured more than 4000 detail points, from the villas to the cistern system. Polaris geodetic astronomy helped us determine true north at the highest ground control. We stored the measured data in REC modules, and later transferred them by means of a Leica GIF interface to a notebook computer for processing. Software developed at our institute allowed us to convert the measured data into coordinates.
In the fortnight available, we did a detail survey of the remnants of the buildings that had formed level rectangular terraces or craters on the hill when they collapsed. A manual plot of all the detail points surveyed would have taken far too long. But just before flying to Syria, we had received a test version of LISCAD and had brought it with us. We therefore decided to use this software to plot the data. Though there had not been time to familiarize ourselves with this software, after the first day’s surveying the notebook’s monitor gave us a fair representation of the ground we had surveyed so far. The program’s detailed, comprehensive on-line help proved most useful when we were at our wits’ end, and the rest we found out by trial and error. This invaluable tool enabled us to make a complete map of the ancient town of Al Hallul. We plotted the ground plan in colour, complete with codes, marks, and symbols, the old and new and buildings, the network of lanes, cisterns, and other features.
Though some walls were only partly recognizable, it proved possible to produce a satisfactory reconstruction of the ground plans from the many data we had obtained of ancillary points, and the program’s Terrain Model function helped us plot the contours of the terraces that had formed. After finishing work in the field and at the office, we checked the site plan from the computer against conditions in the field.
LISCAD proved itself as an efficient high-performance software package that can process large amounts of data very fast.
My special thanks are due to Dr Michaela Konrad and Professor Dr Tilo Ulbert of the German Archaeological Institute, for their invaluable help and co-operation, and to the two engineering undergraduates in our team, Christian Gerlach and Michael Hosse.
