Recent excavation and coring of the collapsed east wall of the Saxon Shore fort of Richborough has revealed the manner in which the wall collapsed. This led to a re-evaluation of the original siting of the wall, which must have lain to the west of where it is usually depicted. Reassessment of previous excavations, including the examination of original records from the J.P. Bushe-Fox excavations of the 1920s and 1930s leads to the conclusion that the so-called ‘unfinished’ or ‘abandoned’ east wall foundation was in fact the base of the built east wall, from which the collapse derives. A revised fort plan based upon this conclusion is suggested. Supplementary material is available online (https://doi.org/10.1017/S0068113X20000379), and includes additional backing tables and illustrations referenced in the text.