Alcatraz Island

Alcatraz Island is a small island in San Francisco Bay located about 1.25 miles offshore from San Francisco, noted for its 20th-century federal penitentiary. The island covers roughly 22 acres and contains remnants of military fortifications, a lighthouse, and the former cellhouse.

Guided and self-guided audio tours of the former cellhouse interpret the federal prison era from 1934 to 1963 and include access to cell blocks, guard stations, and related exhibits. Other interpretive features cover earlier military uses, the island’s lighthouse, and later historic events including a Native American occupation in 1969.

Visitors reach the island by scheduled ferries from San Francisco piers; the short ride provides bay views and approach perspectives of the island. On-island circulation is on foot with interpretive trails and guided-program schedules.

Originally fortified and used by the U.S. Army in the mid-19th century, the island later became a federal penitentiary in 1934 and was closed as a prison in 1963. The site’s layered history includes maritime navigation, military defense, the federal prison era, and later preservation and public interpretation.

Situated in San Francisco Bay near the city’s northern waterfront, the island is a short ferry ride from the San Francisco shoreline and is managed as part of the national park system.

• Access and size: The island is about 1.25 miles offshore from San Francisco's Fisherman's Wharf and covers roughly 22 acres, requiring a ferry ride for visitor access.
• Historic periods: The federal penitentiary operated from 1934 until 1963, and the island also hosted a well-known Native American occupation beginning in 1969 that is part of its modern history.

What to See #

• Cellhouse: The former cellhouse and prison complex that housed inmate cells, corridors, and guard stations and is the primary focus of guided and audio tours describing the federal penitentiary era from 1934 to 1963.
• Lighthouse: A lighthouse on the island that dates to mid-19th century navigational use and predates the federal prison; it is one of the island's oldest structures.
• Fort and parade ground: Open parade ground and batteried fortifications dating to the island's use as a military fort in the 19th century, interpreted on guided tours and exhibits.