Alcatraz Federal Penitentiary, located on a rocky island in San Francisco Bay, operated as a federal prison from 1934 to 1963 and held some of America's most notorious criminals, including Al Capone, Robert 'Birdman' Stroud, and George 'Machine Gun' Kelly. The prison's harsh conditions — cold isolation cells, strict silence rules, and the constant psychological torment of being able to see San Francisco but never reach it — created an atmosphere of suffering that many believe persists. Since Alcatraz became a national park, rangers and visitors have reported extensive paranormal activity. Cell Block D, the solitary confinement unit, is considered the most haunted area.
Rangers describe hearing screams, crying, and the clanging of cell doors in the empty block. Cell 14D, where an inmate reportedly died under mysterious circumstances, is said to be intensely cold — sometimes 20 degrees colder than adjacent cells. Visitors have described hearing a banjo playing in the shower room (where Al Capone reportedly played his banjo) and seeing the apparition of a man in prison grays in the corridors.
The lighthouse and the ruins of the military prison that predated the federal facility have their own ghost stories. Alcatraz receives over 1.7 million visitors annually, and ghost reports are collected regularly by the park service.