9. Alcatraz Island – San Francisco, California
Alcatraz Island started as a fortress for the Civil War and became a military and federal prison until 1963 (via Oyster). Ferries can take you to and from the island. Enjoy guided tours to learn more about the history. Alcatraz Island is also considered one of the most haunted prisons in America, as many criminals lost their lives within the cells. If you’re brave enough, you might want to schedule one of the haunted tours of the island when the sun has gone down (via Oyster).