This is another photo that I took on Governor's Island. This is Castle Williams, constructed in 1807 and named after its designer Jonathan Williams. It was the first fort of its kind in the U.S. and its circular shape helped to deflect cannon balls. To test his design, Williams had Navy ships fire cannons into the fort, as he stood inside. Apparently it was very sturdy. During the civil war it was used as a holding facility for confederate prisoners. In 2001, the fort and its surroundings on Governor's Island became a national monument.