This large midwestern cavern features impressive rock formations and an underground waterfall.

An old soap company building now houses one of Minneapolis’s oldest independent non-profit art galleries.

These curious caverns have been home to mushrooms, gangsters, and disco.

A sculptor's dream castle turned fantastical ruin.

These Great Lakes sea caves accessible by boat in the summer turn into temples of ice reachable by foot in the winter.

Crumbling ruins mark the site of a couple's grisly murder in the woods.

The remains of one of America's first radiation testing grounds still rest ominously in a Georgia forest.

Just a few miles from downtown Atlanta is a trail covered in a crazy collection of outsider art.

The final resting place of New Orleans' most famous voodoo priestess.

A 200-year-old building in the French Quarter that was to be Napoleon's home in the New World.

The Devil’s own choice when he needs a drink in Brussels.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

An underwater restaurant, surrounded by a coral reef.

Disused penal colony features prisoner artwork, some sketched in human blood.

This neon blue river gets its color from a unique mix of bacteria and volcano minerals.

Sloth rehabilitation center in the jungle of Costa Rica.

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

Enormous lake at the bottom of a unique cave system.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Once known as the Illinois Asylum for the Incurable Insane.

This abandoned 19th century orphanage started as a boarding school for children of Civil War veterans.

What was once one of the country's largest confectionary plants is now an abandoned ruin, but is still pretty sweet.

What may be America's largest classic video game arcade lurks inconspicuously in a Chicago suburb.