Alcatraz Island is about 1.25 miles (2 km) away from the shores of San Francisco and has been used as the site of a lighthouse, military base, military prison, and federal prison before being designated as a National Historic Landmark in 1986. Its most famous use was as the Alcatraz Federal Penitentiary, which was specifically used to house the most difficult prisoners from institutions around the nation. Due to the dangerous nature of the freezing water and tricky currents surrounding the island, the prison became known as inescapable, and although there were many attempts over the years, there’s no evidence that any of the potential escapees made it to the mainland alive. The prison closed in 1963 after another escape attempt and the publication of reports that Alcatraz needed an expensive refurbishment in order to stay open, plus operating costs for the island prison had always been higher than for other penitentiaries. From 1969 to 1971 the island was occupied by Native American protesters who argued that any abandoned or out-of-use federal land should be returned to the native people from whom they were acquired. During this time some of the buildings were damaged, and visitors will still be able to see graffiti from the protests on some walls as you visit the site. Today various American Indigenous groups hold ceremonies on the island, in particular on Columbus Day and Thanksgiving Day. It’s also become one of San Francisco’s most popular tourist destinations, with 1.8 million tourists visiting annually. The island and the prison have a unique position in the American cultural imagination, featuring in plenty of books, TV shows, and movies.