South Tower House

South Tower House is a house built around 1718, with alterations made in the late 19th century. It is constructed of English bond brick, featuring a late 19th-century brick lateral stack and a slate pyramidal hipped roof. The building has a single-depth plan and stands three storeys high with a two-window range. The exterior includes battered ground-floor buttresses, a plat band, and a second-floor Lombard frieze above a band of shallow rectangular recesses. Late 19th-century segmental arches have been inserted above 6/6-pane sashes. There are two blocked first-floor oculi on the south and north sides, and a wide, blocked round-arched gateway on the ground floor to the west. A single-storey late 19th-century red brick gabled extension is attached to the south, featuring a 2/2-pane sash window. The interior has not been inspected.

Historically, South Tower House is part of the eastern perimeter wall that includes the North Tower House and Gatehouse, constructed during the early 18th-century expansion of the Dockyard. This wall originally enclosed the Yard and included towers at the corners, each with pairs of oculi on the external faces and a crenellated parapet. The structure illustrates the need for protection of the Yard prior to the construction of the mid-18th-century Chatham Lines.