This crack in France's seaside cliffs once hid a sinister secret.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

A castle-like sea fort from the 17th century is now a museum to oyster farming.

Another entry into the world of Edinburgh's pop-up artworks.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

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

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

The oldest Roman lighthouse still in use.

This abandoned naval battery stood at the ready as recently as the 1980s.

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

Iron Age runes and ruins hide in plain sight along this Portuguese beach.

Picturesque intersection of witchcraft and ancient Christianity.

One of the largest Roman settlements in Portugal.

A windswept necropolis carved into the rocks overlooks the "most Portuguese town in Portugal."

The best place in the world to buy tinned fish.

This charming candle shop has been in business since 1789.

The world's oldest bookshop still in operation.

Houses are tucked between, on, and underneath giant boulders.

You can cross from one country to another in a single hop on this little bridge.

A unique seaside cave where Aleister Crowley faked his own death.

An abandoned mine now resembles a post-apocalyptic landscape of derelict buildings and blood-red pools of water.

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

Dead weights honor the dead of Portugal's fishing industry.