High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

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

Paris' fabled purveyor of exotic taxidermy and natural history curios.

Marie Antoinette and Napoleon Bonaparte were fans of this 200-year-old French chocolatier.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A museum of magic with a Sadist past.

Dedicated to the art of hunting, with juxtapositions of contemporary art.

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

A curious collection dedicated to human and animal anatomy and pathology.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

This 18th-century fort surrounded by a moat was used to store gun powder and ammunition, and now sits in the middle of a large park in Dublin.

The chaotic studio of one of the 20th century's most important artists has been preserved down to the dust.

See some of the world's greatest racing horses at this idyllic thoroughbred breeding facility and garden complex.

An industrial relic is now one of Europe's most staggering art spaces.

The world's biggest pet store.

This former steel and coal plant is now a neon-lit industrial fantasia.

Largest illuminated advertisement sign in the world.

The monumental home of Prussia’s eccentric "Cannon King."

An electrical pylon under whose legs a normal gauge train can run.

An abandoned underground bathroom is now a space for public art.

This futuristic German television spire is actually the world's largest digital clock.

Twisted buildings adorn the banks of the Rhine river.

This concrete church spent a period of its history as a World War II bunker.