A watching brief was undertaken by Colchester Archaeological Trust during the excavation of footings trenches for two new buildings in the former Cavalry Barracks (Alienated Lane Area J1), Colchester Garrison. The two new buildings are to the rear of and between some of the retained Garrison buildings, that is, the Old Riding School, the old Sergeant’s Mess, and two of the stable buildings. Footings trenches were dug to 1.15m below modern ground level. This exposed a post-medieval or modern layer varying in depth between 0.50m and 0.70m, directly overlying natural gravel and sand. This post-medieval or modern layer comprised dark brown loam interleaved with modern demolition material. It also contained tile, brick and charcoal. A depth of 0.4m was later stripped off the site. This exposed an L-shaped trench aligned NW to SE and NE to SW. This was probably the grubbed-out footings of a building shown on the OS 1:10,000 map which has subsequently been demolished. Areas of modern demolition material and featureless loam were exposed on the rest of the stripped surface. Examination of spoil heaps yielded modern finds and post-medieval bottle glass. <1>