Point Lookout State Park is located at the southern tip of St. Mary's county in Maryland. It is a peninsula formed by the confluence of the Chesapeake Bay and the Potomac River. It's a popular summer destination for fishing, camping, and cooling off in the river (although not everywhere as seen above).
During the Civil War, Point Lookout was a Union Prison of War camp. Over 50,000 Confederate soldiers were held there, and according to Maryland Dept. of Natural Resources close to 4,000 soldiers died at the POW camp.