Alcatraz Island

former maximum-security prison in San Francisco

Generally known as Alcatraz, this island is 1.5 miles (2.4 Km) offshore from San Francisco. Once a maximum-security federal prison housing notorious criminals the likes of gangsters Al Capone and "Machine Gun Kelly", it's now a historic and recreational site.

5,000 people visit it daily, probably a few more than when it was a prison.