A natural gas leak provides a flickering flame beneath a waterfall.

The remains of a failed subway in upstate New York is now an underground graffiti bunker.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

This museum devoted to the gothic author holds such interesting ephemera as his socks and walking stick.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

This replica of the Greek structure is in the heart of Nashville.

World War II bunker still standing on the New Jersey beach.

The rusting remains are visible sticking out of the waters of the Delaware Bay.

World's first "penitentiary," meant to be humane, drove men insane.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

The first of Lancaster's "rural cemeteries."