Fort Delaware

Built to guard the mouth of the Delaware River, Fort Delaware became a Union prison for Confederate soldiers during the Civil War, holding almost 33,000 men over the course of the war on Pea Patch Island, more than 11,000 of them at one time in August 1863, under conditions bad enough that the site is sometimes called the Union's answer to Andersonville; about 2,500 prisoners died here, many from typhus and malaria, and were buried in a cemetery that once stood on the island. Now a state park reached by ferry, the fort runs its own paranormal tours. Visitors and staff report footsteps, shadowy figures, cold spots, and disembodied voices throughout the ramparts, along with a ghost staff call Susan, seen in the kitchen; on one recent tour, visitors reported seeing the figure of a Confederate soldier watching from the upper ramparts.