In advance of the proposed redevelopment of the eastern side of the Williams & Griffin (Fenwick Ltd) department store, 147-155 High Street, Colchester, seven test-pits (number TP3-TP9), each initially 2m x 2m in size, were excavated to ascertain the depth and level of survival of archaeological deposits beneath the existing store (CBC planning application 121902). In addition, four boreholes were undertaken by geotechnical investigators and monitored and recorded by a CAT archaeologist. The investigations took place within the store, on surrounding land, and in the adjacent Colchester Borough Council (CBC) car park.<1> Near the High Street frontage, the construction of the basement beneath the south-western part of the store was found to have removed all potential archaeological deposits. Further to the east, evidence for a possible backfilled basement on the High Street frontage was identified. However, previous investigations during the construction and conversion of the former Jacklins store on the High Street (currently within the proposed development area), found a substantial medieval stone building and the remains of a Roman pottery shop destroyed in the Boudican rebellion of AD 61.<2> The survival of these remains suggests that at least some of the High Street frontage has not been previously basemented. The construction of the current buildings on the eastern side of the modern store appears to have had little impact on archaeological remains. Away from the High Street this is primarily due to the depth of 19th/20th-century deposits beneath it. Within the boundary of the department store, the 19th/20th-century deposits associated with the oldest iron foundry to be built in Essex (1792) were c.1.4m deep. In the CBC car park, the floor surfaces and wall foundations from the outbuildings of the former Cups Hotel were c.1m deep. A layer of dark soil containing finds dating to the medieval and post-medieval periods underlay the 19th/20th-century contexts, and only three archaeological features dating to these periods were identified. This suggests that most of the area evaluated was located in open area behind the buildings that fronted the High Street during the medieval and post-medieval periods. Roman contexts were identified across the evaluation site at an average depth of 2m below modern ground level (between 1.1m and 2.7m), although in some instances it is possible that deposits described as Roman could be later truncations. The uppermost Roman deposits were overlain by a dark earth containing late Roman finds. No Anglo-Saxon or early medieval finds were recovered from the dark earth or as residual finds in later contexts. Based on this limited evaluation, it is probable that extensive Roman building remains survive beneath the existing store. Most of the deposits assigned to the Roman period contained significant quantities of brick/tile fragments and mortar, and have been interpreted as debris from the demolition of Roman buildings. Solid deposits, probably building remains, were encountered, and fragments of a mosaic pavement were identified during borehole sampling to the north of the store.