A unique underground structure dating back to the 1st century BC.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

The world's most famous cheese caves.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

Oldest Museum of the Netherlands is a true cabinet of curiosities.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Historic medieval fortified city in southwest France.

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Site of one of World War I's most horrific scenes.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

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

Museum in a swimming pool where the water still flows.

France's most famous cemetery, with some of its most curious tombs.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

France's Lilliputian park displays over 100 of the country's monuments for visitor perusal.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

Supposed home of the camel ridden by Napoleon during his Egyptian campaign.

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

Figures of unknown origin carved into the surfaces of underground caves.