Of all the Norican fort-vicus settlements in Austria, only that of Asturis-Zwentendorf was never built over in the mediaeval or modern periods. Although the northern part of the Fort - and indeed also the vicus - has fallen victim to erosion by the Danube, an extensive vicus-settlement, covering an area of ca. 30 ha., must have existed to the east, south and west of the fort. Zwentendorf thereby offers a unique opportunity to investigate the total development right up to its borders by means of a geophysical prospection which conserves the finds; and to compare the results of this investigation with those of other vici, above all Favianis/Mautern, where for the first time it has been possible during recent excavations to examine a large area of the fort-vicus structural development. The project, undertaken jointly by the OEAI (archaeology), the Institute for Pre- and Early History/Aerial Image Archive (aerial image interpretation) and Archeo Prospections® (geophysics), is composed of a number of steps: in step one, an interpretation of the aerial images of Zwentendorf was undertaken by M. Doneus; connected to this, Archeo Prospection carried out geophysical measurements. The geophysical prospection for 2001/2002 incorporated measurements with a caesium-gradiometer-magnetometer system based on a grid of 12.5 × 50 cm., whereby an area of ca. 10 ha. in the environs of the auxiliary fort of Zwentendorf were examined, and detailed areas inside the camp were measured with georadar (2002).
The measurements, supplemented by the aerial image interpretations, gave a preliminary overview of the organization and arrangement of the vicus buildings. Three streets branched off to the south from one of the roads which ran past the south flank of the camp in an east-west direction. Alongside these, it was possible to recognize that the land was parceled in strips of ca. 10 × 50 m., in a comparable manner to the arrangement in the East vicus of Mautern. The development of the land parcels must have been carried out almost exclusively with wooden structures, for numerous, in part rectangular pits can be recognized in the areas near the streets; these, via analogy with the vicus of Mautern, must have belonged to "pit houses" (Grubenhäuser). Along the exit road from the camp's south gate, the first grave structures were located, at a distance of ca. 250 m. from the camp.
In the last stage of the project, in cooperation with the Institute for Classical Archaeology of the University of Vienna, a ceramic survey was carried out over an area of 8 ha. to the south of the camp along the line leading to the Limes Road. The analysis of the ca. 4,000 finds has led to important conclusions concerning the usage of the settlement and burial areas in the mid-Imperial period and in late antiquity. The oldest settlement is assumed not to have occurred prior to the late Flavian or Trajanic period. During the mid-Imperial period, the zones of activity within the settlement area were relocated, so that the concentration of finds of Antonine date along the southern road were replaced by a similar concentration of Severan date along the East-West road. Contacts, in particular with the neighbouring Pannonian province, are attested in the mid-Imperial period. The phenomenon which has been documented in the vicus Favianis-Mautern, of a decrease in the presence of finds immediately after the Marcomanni wars, cannot be proven in Asturis-Zwentendorf. In the late 3rd and in the 4th centuries A.D. a smaller-scale usage of the settlement area, albeit an equally intensive one, took place.

Picture Captions
Fig. 1: Results of the aerial picture analysis (© M. Doneus) and of the geophysical prospections (Archeo Prospections®) up till 2002
Fig. 2: Detailed view of the geophysical prospections with archaeological interpretation (Archeo Prospections®)
Fig. 3: Ceramic survey 2005 in the vicus of Zwentendorf (© ÖAI, St. Groh)

Bibliography:
H. Stiglitz, Das römische Donaukastell Zwentendorf in Niederösterreich, RLÖ 26 (1975).
St. Groh, Die Vici von Mautern und Zwentendorf - ein Vergleich norischer Kastellvici, in: St. Groh - H. Sedlmayer, Forschungen im Vicus Ost von Mautern-Favianis, RLÖ 44 (2006) 174-178.