Built in 1901 as an expansion onto the Washington Aqueduct’s receiving reservoir, the Castle Gatehouse is a rare example of architecture based on a government logo, the castle that appears on the 1839 insignia of the Army Corps of Engineers. The castle gatehouse was originally built between 1899 and 1901 using face brick as its exterior surface. In order to give the building the authentic look of a typical ancient castle, the brick surface was covered with Portland cement plaster blocked off to represent stonework. In 1958 the old stucco was removed, and a new coat of gray stucco was applied to the brick surface and similarly blocked off. The intentional resemblance of the gatehouse to the Army Corps of Engineers insignia allows the building to serve as a symbol of the Army Corps' contributions to the city's public health.
DC Inventory: January 29, 1974
National Register: March 13, 1975