A programme of archaeological monitoring was carried out by Colchester Archaeological Trust at Duncan’s Gate, Castle Park, Colchester in September 2017. The monitoring focused on the conservation of collapsed masonry to the south of the gate, which has been interpreted as the remains of the gate tower (MCC10068). The cleaning of the collapse prior to the reattachment of several tile courses allowed a section to be recorded, providing an accurate depth of the collapsed masonry. Two layers of loose soil were also recorded associated with the construction of the modern retaining wall around the collapse.<1>