This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

An enchanting landscape of ancient sandstone structures eroded into otherworldly shapes.

Rumors and legends of secret Nazi activities surround this eerily remote island mansion.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

Semi-mystical manmade towers of rocks decorate this rocky seaside.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

Hundreds of caves once used to store grains and animal feed.

An arresting arch punched straight through a mountain provides one of the most scenic spots, and challenging climbs, on the planet.

These striking ruins of a castle resemble a ship's stern.

An ancient Roman theatre restored to its former glory in the Spanish city of Cartegena.

Geological storytelling.

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

This ancient Spanish castle sits high upon a hilltop.

On La Gomera, "Silbadors" communicate in a 4,000-word language of whistles.

Rare karst landscape eroded from a flat seabed.

Devastated landscape used for hundreds of years by the Romans as their primary mining site.

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

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

Village situated on a narrow volcanic escarpment.

Cliffside houses provide a spectacular view from their perch above the valley.

An isolated village literally built into the crevices and rock formations of a mountain.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.