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

One woman's decades-long obsession with the "La Fée Verte."

This is what trains will look like after the zombie apocalypse.

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

The floorboard scrawling of a tragic madman is on public display outside a Paris hospital, much to the dismay of its opponents.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

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

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

One of the oldest masonic museums in Paris.

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

Museum in a swimming pool where the water still flows.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

A self-built mosaic house and sculpture park.

The world's largest reflecting pool is just two centimeters deep.

The world's tallest bridge is also possibly the most elegant.

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.

Saintly bones pressed into a wax effigy of a Catholic superstar.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

This bridge was constructed from the rubble of the infamous Bastille.