The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

2300-year-old Roman road connecting the empire.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

The yawning maw of this pagan visage is said to bite off the hands of liars.

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

The tiny Belgian town's ancient version of Mardi Gras involves eerie wax masks, sticks for warding off evil, and ostrich plume hats.

Longest canal tunnel in the world, abandoned in the 1960s.

From carts to cars, this leftover Roman bridge in France has managed to survive for centuries.

"Drunken ship" sculpture memorializing the French poet in the city where he died.

This folk museum is devoted to small figurines of provincial village life.

This workshop and small museum is dedicated to tiny, delicate figurines that began as a subversive craft after the French Revolution.

A French library that makes sure its love of books is writ large... giant in fact.

Balconies that have a most unusual accent.

Sleep in a climate-controlled plastic bubble for the night.

Now a memorial, this factory was once used as a concentration camp for artists by the Vichy government.

A wood-and-steel sculpture garden featuring an artful interplay of nature and machinery.

What if all public housing projects had been designed by "the Pygmalion of modern architecture," not only their prototype?

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The central mosque of this Mali town is entirely built from mud.

These homes carved into the mountains seem to defy the laws of nature.

Ancient Manuscripts showcase the civilization of West Africans during the Middle Ages.