Visit this playground of waterfalls, caves and sinkholes.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

San Francisco Bay's ghost town.

A French chateau, failed utopian community, odd museum, and Stonehenge replica in rural Washington State.

A whimsical village of unique treehouses resides in a Washington forest.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

The remains of a ruined mansion memorialize the 1906 earthquake.

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

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

This family mausoleum is steeped in symbolism and looks more like a fantasy location than a grave.

One of the ghostly stops along Route 66.

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

These millipedes glow not out of attraction, but as a not-too-subtle warning.

The site of murders and Satanic cult gatherings.

A stealthy Apache hideaway that became the haunting site of a mass grave.

One of the last Jazz Age "Wonder Theaters" in New York City.

A futuristic temple of light uses prisms and rainbows to create an atmosphere of peace.

Stay in a room with a view... of the bottom of the ocean.

A piece of outsider public art accompanied by a strange urban legend.