Building 129 (Guard House), South Barracks

The Guard House, also known as Building 129, is located in the South Barracks and was built in 1861, with a Detention Block added in the late 19th century. It is constructed from yellow stock brick and features brick ridge stacks and a slate hipped roof. The building has an L-shaped single-depth plan and is a single storey. The guard house includes a 4x7-bay verandah supported by cast-iron columns, with two doorways at the center of the long side, each flanked by small lights, and a 6/6-pane sash window at the end. The detention block has small segmental-arched lights with iron frames positioned high beneath the eaves of the cells. Although the interior has not been inspected, it is reported to contain original room divisions. This guard house is one of only two examples built by the Barracks Department at the start of the Revolutionary War with France and is part of a group that includes the Officers' mess and infantry and cavalry barracks, making it one of the most complete late 18th-century barracks in the country.