The castle gatehouse was originally built between 1899-1901 using face brick as its exterior surface. In order to give It an 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. It was designed to resemble the 1839 insignia of the Army Corps of Engineers and serves as a symbol of the Army Corps' contributions to the city's public health.
Restuccoed in 1958.
National Register: March 13, 1975
DC Inventory: January 29, 1974