This chain of artificial lakes was an ideal test ground for the aircraft that would carry the "bouncing bombs" used by the WWII "Dambusters" squad.

There’s a special club house at the top for the bell ringers.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

The largest retailer of seashells in the world.

A plaque commemorates the spot in the Oregon woods where the first-ever Geocache was hidden.

Giant origami crease patterns engraved in Santa Monica intersections may even be visible from space.

A ring of creosote bushes that are estimated to be 11,700 years old.

About 80% of all U.S. avocados are descendants of Rudolph Hass's glorious tree.

At the center of an island in the middle of the Indian Ocean is a deep chasm ringed by tall waterfalls.

What might look like a cliffside sacrificial altar at first glance is actually a stone compass pointing to cities and lighthouses all around the world.

A Himalayan monastery claims to have a piece of a centuries-old abominable snowman.

The giant Siberian crater known locally as the "doorway to the underworld" is expanding every year.

Activists are fighting to preserve these unfinished highway ramps as a tribute to the citizen revolt that halted their construction decades ago.

A subterranean shelter remains intact under a busy Paris railway station.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

The Arctic Circle runs through this isolated spot north of Iceland.

The unbelievably opulent home built for an infamous newspaperman.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

Eyam took steps to quarantine themselves and keep the plague from spreading.

The library's graceful rotunda is like a bibliophile's temple.

An isolated dive site teeming with cnidarians.

A 70-foot-deep ice cave formed by lava from Mt. Fuji on the edge of Japan's "Suicide Forest." 

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

These passages carved from the Antarctic ice hold strange shrines to the harsh southernmost climes.