Fort Warren, Georges Island
Fort Warren, built to defend the area, sits at the entrance to Boston Harbor. A pentagonal star fort of stone and granite, it was completed in 1861, shortly after the beginning of the American Civil War. Fort Warren was active through the end of WWII. During the Civil War it served as a prison for Confederate officers and government officials. It was permanently decommissioned in 1947. The fort was named after Dr Joseph Warren who sent Paul Revere on his famous ride.