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

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Ancient serpentine sacrifice holder that has stood the test of time.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A dangerous narrow-gauge railroad once traced a route through this striking canyon.

A glimpse of a waterfall is reached by a steel catwalk along a slot canyon located in an Ouray city park.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

This automated sculpture of two men peeing will spell out text messages with their micturition.

An eerie, existential museum dedicated to the author of "The Metamorphosis."

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

This spooky statue sits outside a famous Prague theater.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

Throughout this shopping mall are medieval ruins that were discovered during the mall's construction.

The first museum in the world devoted to sexual gadgetry.

A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

Macabre astrological automaton clock dating to the late 1400s.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

A quiet, semi-secret square with statues of Mahatma Gandhi, Virginia Woolf, and a conscientious objectors stone.

This marine reptile was discovered by one of the 19th century's greatest fossil hunters.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.