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

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

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

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

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

Got apples?

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.

Beautiful carved tunnels.

Monsters and miniatures are held in equal esteem at this wondrous museum.

Ghosts of France's colonial past.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

The largest underground church in Europe.

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

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

One of the greatest maze designer’s greatest mazes.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

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

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

19th century pendulum and a clock restored by a rogue group of guerilla artists.