One of the oldest masonic museums in Paris.

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.

Beggars were miraculously "cured" of their fake ailments when they returned home to this 17th century Paris slum each night.

This innocuous-seeming building is actually the remnant of a major wartime brothel.

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

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

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.

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

A public park off the beaten path with a beautiful waterfall and 13th century Cistercian abbey.

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

Beautiful carved tunnels.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

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

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

This banal Parisian entranceway is not what it seems.

The fantastic architectural models of a French traveler.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

Skeletons, medical artifacts, and other obscure and precious treasures all displayed in a wooden pharmacist's cabinet.

Two small chapels housed inside an ancient tree.

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

One of the last umbrella repair shops in Paris upholds the nostalgic art of umbrella making.

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