Each spring this woodland floor is carpeted with purplish flowers as far as the eye can see.

The second-largest natural arch in the Chartreuse Mountains.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

This one-of-a-kind Roman arch is not actually dedicated to the god Janus.

It's safe—and permitted—to walk across these twin natural sandstone arches.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

An exotic jungle hideaway run entirely by indigenous Kichwa women.

This is the oldest Roman-made bridge in the city still existing in its original state.

A unique rock formation that only a few have managed to venture inside.

Every October, one of the largest migration of mammals in the world thunders through Boma National Park.

Seven streams tumble over a cliff, resulting in this dazzling waterfall in the Nigerian rainforest.

The waters of these secluded falls are said to have healing powers.

The walls of this sandstone outcropping are covered with 2,000-year-old artwork.

Ado Awaye Mountain and the unique lake that sits near its peak are shrouded in ancient legends.

Located more than 600 feet beneath sea level, this tunnel boasts the world's first undersea roundabout.

This hill and tower are steeped in legend, from King Arthur to the Holy Grail.

Take a ride back in time with a steam locomotive trip through Eritrea’s mountainous countryside.

What began with a single, 357-pound chunk of the Canyon Diablo meteorite grew to be an impressive collection. 

A small house sits between two huge rocks, with its back to the sea.

In the foothills of the lesser Caucasus, a centuries-old fortress still stands.

A fire lookout atop a glacial pinnacle is reached by climbing three vertiginous flights of stairs.

This scalding hot river was thought to be a myth until one geoscientist made it his quest to study the mystical waters.

Remains of an abandoned coral city.

This is what trains will look like after the zombie apocalypse.