Resting on a hill overlooking the coast, these medieval ruins look completely deserted save for their restored chapel.

Fighting the British and making game shows for over 150 years.

100-windowed castle turned art gallery, built by one dedicated mason.

French commune at the heart of conspiracies.

Bits of architecture from a town destroyed in World War I now decorate this hotel garden.

A centuries-old complex of hand-dug stone chambers has sheltered locals in times of trouble.

Two small chapels housed inside an ancient tree.

The fantastic architectural models of a French traveler.

A medieval military street hidden beneath a charming French fishing village.

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

Do these monsters look familiar? The gargoyles on this church are all from pop culture.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

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

The curious underground history of keeping Paris clean.

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

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

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

This museum houses an imposing skeleton army comprised of creatures great and small.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Abandoned railway line circling the city of Paris.

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

This Sumatran root bridge took almost 30 years to knit itself together.

An abandoned hotel in the highlands of Bali is shrouded in stories of ghosts, curses, and corruption.

The historic building has preserved human organs, unusual hexagrams, and scars from a political assassination.