This maze-like slot canyon is a unique gem within an already fascinating geological area.

A blacklight journey through a celestial art exhibit.

A Texas cave network is home to some of the world's most spectacular-looking and bizarrely named mineral formations.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A miniature rainforest is growing inside of a Midtown Manhattan office building.

A few dilapidated structures are all that remain of this deserted former silver mining town.

An Idaho legend carved out a cave village with his own two hands.

This set of hot springs also comes with fantastic views.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

Ancient barriers wrap around what was once an important stop along the Silk Road.

Light still pours into the ruins of this ancient Islamic observatory.

The Avenue of Mausolea is a series of grand palatial tombs.

Looking for a unifying history, Uzbekistan finds its answer in a 14th Century Turco-Mongol conqueror... despite the fact he wasn't Uzbek.

This isolated and westernmost point of the Faroe Islands archipelago is home to thousands of seabirds.

Legend says this rock spire is the finger of a witch who wanted to throw the Faroe Islands towards Iceland.

Two massive boulders, rocking back and forth with the ebbing of the sea.

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

The narrow passages will challenge even the bravest driver.

This mysterious, medieval cathedral remains unbuilt but fiercely protected.

Despite finally receiving electricity in 1970, this tiny town is now deserted.

In Faroese legend, this sinister horse-shaped beast lures unsuspecting passersby only to drown them in the lake.

The abandoned village of Skarð aptly illustrates the idiom "Don't put all your eggs in one basket."

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .