Arhcaeological monitoring and recording was undertaken by Colchester Archaeological Trust in December 2017 and January 2018 during geotechnical groundworks at the Mercury Theatre. Monitoring of four of the window sample boreholes (0.4-0.6m wide) and the two boreholes revealed modern horizons to a depth of 0.6-1.25m below current ground level (bcgl). Beneath these horizons were Roman contexts ranging from 1.15m to 2.05m thick. Natural was recorded at depths of between 2.1-3.15m bcgl. Two of the window sample boreholes were excavated through the backfill of an early 19th-century reservoir; the backfill sealed natural which was recorded at depths of c 2.7-2.8m bcgl.<1>