Four trial-pits were excavated by the Colchester Archaeological Trust in May 2019 immediately to the south of Colchester Castle in Upper Castle Park, to inform on the feasibility of a proposed scheme to install new lighting.<1> Foundations belonging to the Castle forebuilding were identified below the modern turf/topsoil in two of the trial-pits (TP2 and TP3). In TP2, the foundation was c.200mm below modern ground level (bmgl). In TP3, the foundation below the doorway of the forebuilding was 140mm bmgl; 0.6m to the east, the top of the same foundation was level with the current ground surface. TP1 was located inside the forebuilding and was excavated through dark, sandy silt soils containing 19th/20th-century finds, down to the maximum depth of 0.4m bmgl; It is likely that TP1 was located within a backfilled 20th-century archaeological investigation, possibly the 'shaft' sunk against the south face of the keep in 1932 to establish the nature of the Castle foundations. In TP 4, to the east of the castle forebuilding, a 20th-century topsoil overlaid a layer of redeposited natural sand mixed with septaria and Roman brick and tile fragments. This deposit may correspond with the fill of a vertical-sided shaft or trench identified during archaeological investigation to the east in 1977, which was interpreted as part of J.T. Round's explorations in the 19th century.