EDO3907 - Colliton Street Youth Centre, Dorchester; evaluation 1998

Wessex Archaeology undertook an archaeological evaluation at Colliton Street Youth Centre in advance of the proposed redevelopment of the site. The evaluation comprised four machine-dug trenches, totalling 20m in length and averaging 1.7m wide (totalling 2.3% of the site area). Chalk bedrock was recorded in the base of all four trenches and a natural drop of 2.19m was recorded from the south to the north of the site. The trenches were numbered 1, 2, 4, and 5. Trench 3 was not excavated. No evidence for prehistoric activity other than a single residual worked flint was recovered. Roman features comprised two postholes and a third undated posthole, which was probably also of Roman date. There was no indication of the survival of stratified Roman deposits. A small assemblage of residual Roman finds was recovered, including pottery of 1st-4th century AD date. The principal features recorded were two substantial ditches in the north of the site. They were both aligned approximately northwest to southeast and were at least 3 m wide. The more westerly ditch was at least 2 m deep below the top of the chalk bedrock. No dating evidence was recovered from either ditch, although their alignment and dimensions suggest they were part of the defensive ditch system of the medieval castle of Dorchester. Apart from the castle ditches, no medieval features or deposits were identified, though there was a small assemblage of residual medieval pottery. The remaining features and deposits were certainly or possibly of post-medieval date. These comprised a ditch and possibly two walls. A small assemblage of 16th-18th century pottery was also recovered.