A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

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

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

Nestled in the mountains of Portugal is a tiny village made almost entirely of schist.

A cluster of granite granaries perched on stilts.

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.

One of Europe's oldest yew trees has lived more than 2,000 years.

A spectacular walk on the flank of a gorge.

Stormy conditions send jets of seawater bursting through holes in the cliffs.

A small church ornamented with medieval erotic sculptures.

A charming Spanish village sits atop this natural limestone overpass.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

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

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

Abandoned Nazi train station turned underground astroparticle laboratory.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

This 5,000-year-old tomb once had its own hinged door.

Beautiful carved tunnels.

An aluminum skeleton brings Chinese mythology to the French shore.

An isolated 17th-century chapel on a remarkable site once dedicated to Celtic sun worship.

One of the great treasures of Neolithic art lies within this carefully constructed pile of rocks.