This sprawling settlement of around 30 hectares lies on south bank of the River Kennet, at the crossroads formed by two major Roman roads; running east-west from Calleva Atrebatum (Silchester) to Aquae Sulis (Bath), and south-east to north-west from Venta Belgarum (Winchester) to Corinium Dobunnorum (Cirencester). There were potteries a short distance down the Silchester-Winchester road to the south-east at Savernake (SU2264) and other pottery kilns further along at Tottenham (SU2463). (O.S. maps)
Aerial photographs show streets and dwellings both inside and outside the defensive circuit of the town, though the sequence of building has not yet been determined. A.P.'s also suggest that the defences surrounding the nucleus of the town had at least two incarnations, the first of turf, the second of stone, upon a slightly different alignment and incorporating multangular bastions regularly spaced every 120 feet (c.36.7 m) along the enclosing wall; both of these aerial observations were subsequently confirmed by excavation. The defences comprised of a rampart fronted by a double ditch, visible on A.P.'s on the south, east and west sides, defined a rectangular area measuring some 870 feet from east to west by about 700 feet transversely (c.265 x 213 m), with rounded corner-angles (again visible on A.P.'s) at the two southern angles. The defended enclosure of about 14 acres (c.5.6 ha) is suspiciously military in outline but no finds of a proven martial nature have been forthcoming. (JRS 1953 pp.90-91)
Plans for the defensive circuit have yet to be published, but sections across the defences have shown that there were two distinct phases:
