The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

Headquarters of the legendary clairvoyant's readings, spiritual hospital, and massage school.

Under a playground is a little-known sealed train tunnel that likely contains the bodies of workers trapped by cave-ins.

Take an otherworldly journey in a school dedicated to out-of-body experiences.