Naval Hospital Oakland, also known as Oak Knoll Naval Hospital, was a U.S. naval hospital located in Oakland, California that opened during World War II (1942) and closed in 1996 as part of the 1993 Base Realignment and Closure program. The 167-acre (68 ha) site is bordered on three sides by Mountain Boulevard and Keller Avenue in the city's Oak Knoll section and its map coordinates are 37°46′05″N 122°08′46″W / 37.768°N 122.146°W. A large main hospital building was started in 1965 and opened in 1968. The base was closed in 1996 in an official Navy ceremony.