This colorful but controversial ceiling has been likened to a 21st-century Sistine Chapel.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Notorious artist squat renovated into legal studios.

This massive library holds what was once the largest book collection in the world.

France's most famous cemetery, with some of its most curious tombs.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

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

There has been an astronomical clock on this spot since the 14th century.

Explore this medieval cathedral by trying to spot all the malevolent monsters hiding in its beautifully colored windows.

Visible below the waves are memorials to the city's Gold Rush dead.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

Men and special assistants stand by the road to sell the day's catch in this lakeside village.

Hundreds of intricately carved Armenian stone crosses can be found within this huge cemetery.

This ancient monastery complex was transformed from an island to a peninsula when the lake was partially drained.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

On high feast days, the entire blue-glass front of this modern church opens up to reveal the small wooden church inside.

This stunning iron gate designed by Modernist architect Antoni Gaudí is filled with mythic symbolism.

Pilgrimage site for star-crossed lovers.

These elaborate gothic monuments honor Verona's medieval lords.