Bits and pieces from the ill-fated Donner Party's winter cabins.

This is not your typical jungle gym.

Less a museum than a bizarre fantasy world created by artists and engineers.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

A cave's rare beauty held a cavernous secret hidden underground.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

This is one really big nut.

Buried beneath the New Mexico sands are believed to be millions of copies of Atari's E.T. video game.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

A historic house left in "dramatic still life."

Museum dedicated to the UK's first charity for abandoned children, with keepsakes of the mothers who left them behind.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

San Francisco Bay's ghost town.

Tenacious mummies survived dental problems, eternal entombment, and more than their fair share of devastating fires.

Law-protected wreckage serves as a peculiar memorial for an almost forgotten World War II tragedy.

This partially buried wreck is one of the most complete of its kind but is only revealed when the sea allows.

A hidden subterranean installation offers a view of the sky.

The taxidermied remains of the "last wild grizzly bear in California" and of the symbol of the state of California.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.