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

A landscape decorated with enormous skull sculptures.

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

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

These ungulates have quite literally bounced back from the brink of extinction.

Replicas of fossils unearthed during renovation work reveal how this area would have looked millions of years ago.

A small house in Tazones, completely covered in shells.

A wonderful collection of fossilized dinosaurs and other creatures that roamed the landscape millions of years ago.

A historic Christian shrine nestled within a spectacular natural cave.

An abandoned Indian-inspired mansion.

See replicas of Europe's most famous cave paintings and even some of the animals that feature in the art.

The surviving remnants of a destroyed medieval church now stand in a public park.

Two large posteriors in one giant statue.

A spectacular walk on the flank of a gorge.

Historic house-museum dedicated to the revolutionary gay graphic artist Tom of Finland.

Over 315,000 preserved amphibians and reptiles in jars.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

Some of the Old West's most notorious outlaws frequented this mining town.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

A wealth of pop culture statuary and green chile dishes give this roadside restaurant clout.

This volcano rises like a giant anthill from the plains below, with a road spiraling up to the rim.