This submersible road connecting a French island to the mainland is lined with safety towers for when the tide strands travelers.

A chapel on a volcanic core, marking the end of a successful journey.

A self-built mosaic house and sculpture park.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

Beautiful carved tunnels.

These quaint French houses dangle precariously over a precipice.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

The fantastic architectural models of a French traveler.

Historic medieval fortified city in southwest France.

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

A Gothic cathedral created from volcanic rocks.

An ancient monastery, a locked room, and a mysterious book heist.

The largest underground church in Europe.

The famous winding walk at Chartres is surrounded in mystery and myth.

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

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

Inside a former cabaret, seven floors of erotic art.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This massive library holds what was once the largest book collection in the world.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

Paris' linguistic guide to the international language of, yes, love.