sentences:  It ceased to be used in 1958 and most of the site was redeveloped in the 1960s, but the keep remained in Ministry of Defence hands and is now used as a regimental museum.It is a Grade II listed building.The Dorchester Depot Barracks were built between 1877 and 1881 on the site of a Militia barracks, which had been established there little over a decade earlier.