Alcatraz Island is located in San Francisco Bay, 1.25 miles (2.01 km) offshore from San Francisco, California, United States. The small island was developed with facilities for a lighthouse, a military fortification, a military prison, and a federal prison, the latter operated from August 11, 1934 until March 21, 1963. The strong currents around the island and cold water temperatures made escape all but impossible. Since the late 20th century, it has become a major tourist attraction.
Today, the island's facilities are managed by the National Park Service as part of Golden Gate National Recreation Area. Visitors can reach the island in fewer than 15 minutes by ferry ride from Pier 33, located between the San Francisco Ferry Building and Fisherman's Wharf, San Francisco. Hornblower Cruises, operating under the name Alcatraz Cruises, is the official ferry provider to and from the island.
Alcatraz has been home to several art installations. In 2014, Chinese artist/dissident Ai Weiwei staged an exhibition which explored "questions about human rights and freedom of expression" called @Large. This exhibition included Lego portraits of famous political prisoners.