A submerged village appears when dam levels drop.

Giant granite sculptures representing family on the northern coast of Spain.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

This architectural beauty is the home to a personal collection of more than 600 examples of mechanical musical instruments.

Perhaps the most spectacular grotto along the Algarve coastline.

Along the most northwestern point in Africa is an ancient cave surrounded by legends.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

An otherworldly art experience.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

The hidden ruins of an old hydroelectric plant reclaimed by nature.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

Aqueducts have dramatically changed this old lake, now home to tufa towers and its very own species of tiny brine shrimp.

Tubing through a cave lit with glowworms is a magical underground experience.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

An antiquated German apothecary on Chicago's North Side.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

A fiery crater has been burning in the Karakum Desert since 1971.

This volcanic cave lake is essentially hard proof that Iceland is the most magical place on Earth.

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

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

A clear blue swimming hole with hidden caves, still unexplored.