The remarkably well-preserved final resting place of a powerful ancient Thracian king.

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

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

This remarkably well-preserved Incan city managed to survive the conquistadores.

A giant concrete orb in far north Iceland marks the ever-shifting boundary.

This historic cemetery built for victims of the epidemics that swept Guadalajara is shrouded in macabre tales.

This charming railway is one of the oldest and steepest funiculars in England.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

Stroll through a wonderland of stupendous moss-covered trees.

Steep canyon walls hide a forested oasis in the West Texas desert.

This crumbling stump is all that remains of what was once thought to be the oldest living organism.

Kentucky, Tennessee, and Virginia meet at this point in the Cumberland Gap.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

When this test site was abandoned, they didn't even bother to take the rocket with them.

This angular Dwarven tunnel cuts through a mountainside in Glacier National Park.

A memorial to the unknown and unheralded men and women of the Cold War military and intelligence services.

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

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

A stairway to heaven, or to nowhere at all.

This shrine to film's most iconic wasteland wanderer is located in the very outback where the movies were shot.

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

A botanic garden full of trees twisted into fantastic shapes and positions.

Home to the "Circus" trees created by Axel Erlandson.

Centuries-old bridges grown from tangled roots.