Even France's favorite aquatic son Jacques Cousteau, couldn't get to the bottom of it.

A private garden of sculptural eccentricities.

This tiny cafe is one of the last meeting places of its kind, allowing revolutionaries a place to plot.

These medieval ruins have survived since the 12th century, even providing shelter from the Nazis.

This mysterious sculpture was thought to symbolize a world ravaged by misery.

The castle where the Marquis de Sade lived out his darkest fantasies.

From carts to cars, this leftover Roman bridge in France has managed to survive for centuries.

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

One man's desire to transcend art led to the construction of this outsider chapel.

Celebrate the end of the Great French Wine Blight with a festival of kissing.

Walk through living pictures and music in the Cathedral of Images.

An 1814 castle that hosts an exhibit of "explorabilia".

The symbolic center of Ireland, this summit also offers panoramic views of the countryside.

This Welsh village gave itself a ridiculous name in a publicity stunt a century ahead of its time.

World's largest working waterwheel has been around for over 150 years.

The remains of the wrecked steam trawler can be found on the beach at low tide.

The remains of centuries of copper mining appear like an alien landscape.

Northern Ireland's Brobdingnagian stepping stones.

A 150-year-old steam locomotive crosses the southern half of the island daily.

This tiny train shuttles passengers to one of Northern Ireland's most spectacular sights.

This World War II relic let Allied pilots know they were entering neutral airspace.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

A harbor town pays tribute to a heroic wartime carrier pigeon.

The atmospheric road was never meant to be so creepy.