Colchester Archaeological Trust undertook archaeological monitoring at Kingswode Hoe School in 2011 during groundworks in advance of the construction of an extension to the north-eastern corner of the existing main school building (Essex CC planning application no CC/COL/92/09).<1> The foundation trenches for the extension were dug using a mini-digger with a toothless trenching bucket. The trenches were 450-500 mm wide, with the exception of several lengths of foundation trench for the southern wall which were 600mm wide. The ground-level within the footprint of the extension was reduced for the ground-bearing slab. The depth of deposits removed varied from approximately 250-300mm in the western part of the site, where terracing for the car-park had taken place, to approximately 600-800mm in the eastern part of the site. The ground-reduction was carried out in two phases by the contractors using a mini-digger with a toothless ditching bucket. Firstly, following the removal of the modern topsoil (L1) and tarmac (L4), the deposits were progressively stripped under archaeological supervision. The top of the natural subsoil lay approximately 250-350mm below the modern ground-level in the western part of the site and approximately 350-500mm deep in the eastern part of the site (ie in places where no significant archaeological or modern features were present). An oval pit (F8) was revealed near the eastern edge of the site during trenching and ground-reduction by machine. It measured at least 0.7m across and 0.6m deep. It was probably cut by the Sheepen Dyke (F12), although it was not possible to confirm this. The surviving part of F8 was excavated by hand, and a single small sherd of probable Bronze Age or Iron Age date was recovered from it. A pit containing a single possible Bronze Age or Early Iron Age sherd was located in the ECC FAU evaluation trench in 2009 (ECC FAU 2010, 6; <2>). This pit lay approximately 3.5m to the south-west of F8. It was not possible to identify it in 2011, as the area had been disturbed by contractors working on modern services. The Sheepen Dyke (F12) extended from NE to SW across the south-eastern corner of the site. It was initially located in the foundation trenches for the eastern and southern walls of the extension. In the latter, it was possible to obtain an almost complete east-west section, 6m wide, through the ditch (Sx 1). The western edge of F12 was subsequently exposed for a length of approximately 10m during ground-reduction. The eastern edge of the ditch and any remains of the bank lay beyond the limits of the site of the extension. The projected total width of the ditch was in the region of 7.0-7.5m x 2m deep bgl. A quantity of pottery was recovered from F12, as well as a few fragments of animal bone, a couple of iron nails and several worked flint flakes. Most of this material was recovered during machining and was not securely stratified. The pottery sherds were largely of Late Iron Age date, especially those from the lower fill. Some sherds of probable post-conquest date were also present, notably in the upper fill. The evidence is, therefore, broadly consistent with a Late Iron Age date for the digging of the ditch and an early Roman date for its backfilling. A pit (F7) was uncovered a metre to the west of the Sheepen Dyke during trenching and ground-reduction by machine. It was roughly circular, approximately 0.7m in diameter x 0.5m deep. A quantity of pottery of mid 1st-century date, including some probable post-conquest sherds, was recovered from F7. Several early Roman ditches were uncovered to the west of, and parallel to, the Sheepen Dyke (F12). Fragments of a ceramic mould, for casting a copper-alloy object, were recovered from the upper fill of ditch F9.