A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Enormous lake at the bottom of a unique cave system.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Continuing the tradition of the dime museum in style.

Get lost in this haunting fairytale art walk through a man-made eucalyptus grove.

The seamy, underground secrets of Portland's criminal past.

The only swimming pool listed on the National Register of Historic Places is emptied and refilled each day with naturally filtered water.

A semi-scholarly approach to sex.

America's most famous piece of self-built architecture.

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

A walk through the historic city center, under the streets of Seattle.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

A bizarre house filled with an astounding array of collections.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

New York's oldest magic store.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.