During the machine groundworks associated with the construction of a new sports facility, a series of Ragstone wall segments were revealed sealed by thick deposits of mixed possible quarry/foundation upcast material. These were plotted onto an overall plan of the new development, and examination of early maps of the prison revealed that all the walling related to the first phase of the prison's construction in the 19th century. These were found to cut into the top of the underlying natural subsoil to a depth of -2.90m below the modern ground surface. Across the area of the development two areas of severe disturbance were recorded, caused by deep foundations to later prison structures and from a large quarry feature, which was possibly for the extraction of either Head Brickearth deposits for brick making or naturally occuring Ragstone used in the outer walls of the prison structure.
Apart from deposits relating to the earliest phase of prison construction, no earlier archaeological deposit or feature pre-dating this was located across the entire development site. [1]

<1> Canterbury Archaeological Trust, 2005, An Archaeological Watching brief during the construction of a new sports facility at H.M.Prison, Maidstone (Unpublished document). SKE12326.