Alcatraz Island lies within San Francisco despite being offshore

Alcatraz Island is located about 1.25 miles offshore in San Francisco Bay but is part of the City and County of San Francisco. The island is administered by the National Park Service as part of the Golden Gate National Recreation Area. The federal penitentiary operated there from 1934 to 1963, and the island remains a well-documented municipal jurisdictional landmass separate from the contiguous city. Visitor ferries to the island depart from Pier 33 (Alcatraz Landing).