One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

A playground inspired by differential calculus dangles from the ceiling of the Liberty Science Center.

These mystical miniature houses bring a touch of magic to the New Jersey woods.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

This hidden gem of a garden has one of the only surviving Victorian ferneries in America.

A living maritime paradox still floats in the same lake where it was built and resurrected... or was it?

Board a mine car and descend the #190 slope 300 feet underground into the Clark Vein of coal.

This lush forest valley was once mined for lumber to the extent that it was once nicknamed "The Pennsylvania Desert."

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

A failed piece of Orientalism has become the proud symbol of a community.

This church in Pittsburgh is home to the largest collection of religious relics in North America.

In which a local geological marvel becomes a quaint roadside attraction.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

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

This permanent exhibition celebrates the finest of our heartless automatons both real and fictional.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

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

Mysterious rocks that ring musically when struck.

A toxic ghost town sitting atop a massive coal fire.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

Giant busts of 42 U.S. presidents are sitting in a field in Virginia.

The skeletal white beams stand as a monument to religious dissent.

The flower-shaped temple in Virginia aims to transcend the boundaries of the world’s religions.