2.4 Ground conditions

The site is located on relatively flat, regularly maintained ground; however, it is prone to high winds, which has led to differential depths of deposits across the site. The bedrock of chalk is overlain by glacial till, with pre-quaternary deposits near the coast (Møller 1986). The fortress and adjacent area is a scheduled monument, while the surrounding fields, and the manor house and gardens to the south are in private ownership. The manor demesne, which includes the fortress, is documented as a crown estate from the late Viking period until it was sold in 1579 (Roesdahl 1986b, 95ff). It has since been in changing private ownership, with cadastral maps documenting the land use at regular intervals since 1803 (Nielsen 1986, fig. 10). The fortress is located in a field that has apparently not been built upon since the Viking period. During the survey, the fortress itself and the field surrounding it were under short grass and there were no obstructions except for the features installed to present the site to visitors: the ramparts, which were marked out in the landscape in 1990 by c. 2m high earthen walls; a large rock, placed to mark the centre of the fortress; a raised viewing platform north of the fortress; and a barbed-wire fence to the south enclosing the manor garden. The reconstructed rampart was too steep to be surveyed, and is seen in the grids as a blank circle without data. A minor road passes immediately to the east of the fortress. The fields to the east of the road were ploughed and harrowed and covered in low crops at the time of survey. With the exception of the garden of the manor house, the survey area thus presented a reasonably level, stable and accessible ground surface.

Figure 19: Location of gradiometer (dark red) and GPR (yellow) survey areas in relation to the current landscape, the reconstructed fortress plan and the excavation plan of pre-fortress settlement. (Map data: © Google Earth)