Alcatraz Island, also known as The Rock, is a rocky island in San Francisco Bay, California, United States

The island had little vegetation and was home to a seabird when it was explored in 1775 by Lieutenant Juan Manuel de Ayala

Sold to the US government in 1849, Alcatraz was the site of the first lighthouse (1854) on the California coast.

 Later other buildings were built on the island and in 1859 the first permanent army garrison was established there. 

 In 1861 the island was designated as an asylum for war criminals.  Later prisoners included 

about 19 Hopi Indians from the Arizona Territory who passively resisted government attempts to assimilate them,

American soldiers fighting in the Philippines who had joined the Filipino cause in 1900.

From 1934 to 1963 it served as a federal prison for the most dangerous civilian prisoners.

Among its famous citizens were Al Capone, George ("Machine Gun") Kelly and Robert Strode, the "Bird of Alcatraz"