Houses are tucked between, on, and underneath giant boulders.

Twice a day a speeding train passes only inches from the homes of this residential neighborhood.

Northern Ireland's Brobdingnagian stepping stones.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

On rare days, this abandoned castle's gatekeepers open its doors, revealing the eye-popping splendor hidden inside.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

These ancient sunken lanes were naturally tunneled into the soft ground by countless footsteps.

A vertically floating hemlock controls the waves and weather at Crater Lake.

A Swiss board game museum housed inside a picture-perfect castle.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

A public display of prehistoric space rocks is named for the Namibian village where they were found.

Travelers leave tea kettles in a remote part of Death Valley as part of a mysterious, decades-old tradition.

At the United Kingdom's only residential library you can sleep among the books.

The half-mile long structure is so impressive, it even shows up on satellite images.

An enormous playhouse designed to look like 21 stacked Lego bricks, with another 25 million colorful Legos inside.

The medieval network of canals hidden underneath the city is opened to explorers each year.

The small sanctuaries lie just off the beaten path near one of Bhutan's most famous attractions.

The taxidermy remains of the first mammal ever cloned from an adult cell are on display in Edinburgh.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

One of the world's oldest and most massive living organisms is a grove of quaking aspens.

A white oak with property rights.

One man's eclectic collection of treasures found at sea.

This tiny business claims to be "the smallest pub on the planet."

The great American road trip, but smaller.