The world's toughest modern Christian pilgrimage leads directly to the gates of Hell.

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

A fifth-century temple improbably built into the side of a cliff.

A small town Romanian cemetery filled with darkly humorous gravestones.

A 120-year-old legend concerning an empty circular patch in the North Carolina woods.

Three bridges straddle a stream, one stacked upon the other.

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

A take-out restaurant that only serves cuisine from countries with which the United States is in conflict.

A museum dedicated exclusively to aircraft used in the military.

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

Mysterious rocks that ring musically when struck.

Penn State's giant bug collection.

A toxic ghost town sitting atop a massive coal fire.

A rare view of a preserved Victorian science museum.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

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

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

Arlington Cemetery exhibit dedicated to death and grieving.

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

The final resting place of two (or three) presidents, one vampire, and 18,000 Confederate soldiers.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

The site of the climactic scene from the classic horror film is now a historic landmark.