A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

A charming Spanish village sits atop this natural limestone overpass.

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

Stunning Roman aqueduct used for 1900 years and still standing.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

A completely underwater art museum sends a stark message about humans' impact on the environment.

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

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

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The earliest known map to show America, discovered by accident at a Paris bookshop.

Village situated on a narrow volcanic escarpment.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

This house's itty bitty size means no humans allowed.

The world's largest wooden structure.

A landscape decorated with enormous skull sculptures.

The morbid items in this small and hidden museum are not for the weak stomached.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

Wonderland replication in progress by one persistent man.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

An architect transformed this abandoned cement factory into his castle-like workshop.

Bacteria and algae give the salty water its bubblegum hue.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.