An archaeological watching brief was undertaken at the County High School for Girls in Colchester during works for an extension to the main building and construction of a new tennis court (CBC planning application CC/COL/0068/01). The whole of the western foundation trench to the extension was monitored. The strip foundations were 800mm wide and 550mm deep. The interconnecting pads were 2.5m x 2.5m wide and 500mm deep. The eastern, northern and southern foundation trenches were not monitored. A trench dug to establish the depth of existing foundations of the main school building was monitored. No features or finds of archaeological interest were observed.<1>