Alcatraz Island Lighthouse Alcatraz Island Lighthouse Alcatraz Island Lighthouse is a lighthouse – the first one built on the U.S. West Coast – located on Alcatraz Island in California's San Francisco Bay. It is located at the southern end of the island near the entrance to the prison. The first light house on the island was completed in 1854, and served the bay during its time as a Citadel and military prison. It was replaced by a taller ( above mean sea level) concrete tower built in 1909 to the south of the original one which was demolished after it was damaged due
Alcatraz Island 1906 San Francisco earthquake, civilian prisoners were transferred to Alcatraz for safe confinement. On March 21, 1907, Alcatraz was officially designated as the Western U.S. Military Prison, later Pacific Branch, U.S. Disciplinary Barracks, 1915. In 1909 construction began on the huge concrete main cell block, designed by Major Reuben Turner, which remains the island's dominant feature. It was completed in 1912. To accommodate the new cell block, the Citadel, a three-story barracks, was demolished down to the first floor, which was actually below ground level. The building had been constructed in an excavated pit (creating a dry "moat") to enhance