Belle Isle, in the James River in downtown Richmond, Virginia, opened as a public park in 1973. During the American Civil War, it was a prison camp for Union POWs. Disease, starvation, and exposure took a toll, and as many as 1,000 prisoners died on the island. In the twentieth century, the Virginia Electric Power Company operated a hydroelectric power plant on Belle Isle. The ruins of the power plant and the nail factory can still be seen to this day. It was added to the National Register of Historic Places in 1995.