Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

This miniature Paris, built out of trash, is one man's two decade labor of love.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

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

A quaint medieval millhouse hovers surprisingly above the waters of the Seine.

A colossal sculptural lion built by the same man who designed the Statue of Liberty.

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

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

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

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

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

The first green space constructed on an elevated viaduct.

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

Historic medieval fortified city in southwest France.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

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

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

A Belle Epoque bordello turned into a themed love hotel.

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

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

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

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

One of the greatest maze designer’s greatest mazes.