Alcatraz Federal Penitentiary was a maximum-security prison on Alcatraz Island in San Francisco Bay that evolved from a fortified military site into the federal system’s "last resort" prison. Built as a U.S. Army prison from 1910 to 1912 and opened as a federal penitentiary in 1934, it held inmates considered especially dangerous or difficult under harsh, highly controlled conditions. Its isolation, cold waters, and strong currents helped give it a reputation as escape-proof and exceptionally severe. The prison closed in 1963, and after a Native American occupation from 1969 to 1971, Alcatraz became a National Park Service museum and one of San Francisco’s most visited historic sites.

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

Photo: Wikipedia · Public domain

San Francisco, California · USA