The federal prison located on Alcatraz Island in San Francisco Bay was permanently closed in which year?

Perhaps the world's most well-known prison, the Alcatraz Federal Penitentiary or United States Penitentiary, Alcatraz Island (or simply 'The Rock'), was a maximum security federal prison on Alcatraz Island, 1.25 miles (2.01 km) off the coast of San Francisco, California, United States of America.

Originally built in 1910-1912 as a U.S. Army military prison, the U.S. Department of Justice acquired the buildings on Alcatraz in 1933. After the buildings were modernized and security increased, the island prison opened for business in August 1934.

Prison operators believed Alcatraz to be escape-proof and America's strongest prison. Over the years, there were 14 known attempts to escape from Alcatraz, involving 36 inmates. The Federal Bureau of Prisons reports that of these would-be escapees, 23 were captured, six were shot and killed during their attempted getaways, two drowned and five went missing and were presumed drowned.

The federal penitentiary was shut down in 1963 because its operating expenses were much higher than those of other federal facilities at the time. (The prison’s island location meant all food and supplies had to be shipped in, at great expense.) Furthermore, the isolated island buildings were beginning to crumble due to exposure to the salty sea air.

The island became part of the Golden Gate National Recreation Area in 1972 and was opened to the public a year later. Today, over 1 million tourists visit Alcatraz each year.