Rare karst landscape eroded from a flat seabed.

Abandoned waterpark turned counter-culture mecca.

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

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

The chefs at El Diablo use heat generated by an active volcano to cook the food.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

Moorish signal station on a stratgic rocky outcrop.

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.

The world's largest wooden structure.

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

Village situated on a narrow volcanic escarpment.

Glowing orb in Minsk houses 8,600,000 items.

A striking Soviet memorial commemorates the liberation of Belarus from the Nazis.

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

Built to ward off Napoleon's army, this city-sized abandoned Russian fort is now perfect for urban exploration.

A railway bridge leading nowhere stands lonely in the middle of a meadow.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

This remarkable prehistoric town is full of watchtowers and houses that have withstood thousands of years.

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

This memorial park stands on the site of one of the largest mass executions of the Second World War.

Curious carved stones and bird-like wings are a symbol of Serbian resilience and freedom on the site of a WWII massacre.

Two distorted Romanesque columns hold aloft a mine cart in honor of laborers who died during WWII.

A forgotten and crumbling Yugoslav monument to the victims of fascism.