The only retired U.S. nuclear missile silo that is open to the public.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

Electrical pylon in the shape of Disney's beloved mouse.

The only runway directly into the magic kingdom has been closed since 1972, but it still sings to you if you drive fast enough.

Disney's abandoned animal island is now an overgrown ruin that was almost the coolest attraction ever.

Hundreds of skulls and bones at the largest skeleton museum in the country.

Human skulls and a stuffed goat made into a rocking chair can be found at this strange little store.

The only ancient owl carving found east of the Mississippi.

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

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

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

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

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

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

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

The ghostly remains of an accidental sea.

New York's oldest magic store.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

The rocks in this arid basin leave trails of movement behind them.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.