Ghosts of France's colonial past.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

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

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

A haunting collection of the vanished and disappearing natural world.

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

Though it may look like a businessman's lost luggage, this case suspended under a highway bridge is actually a contemporary art installation.

See the rare bloom of the "Queen of the Night" cactus at one of the world's largest succulent collections.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Museum devoted to the artificial language of Esperanto.

Op-art architecture designed for happiness.

Handsomely crafted representations of our round planet.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

A fairytale-like medieval church perched atop a rocky cliff on Italy's "Coast of the Gods."

An exhibit of endangered species confiscated from smugglers and passengers.

The world's longest and deepest train tunnel.

Constructed along the shores of Lake Zurich, this pavilion is a walk-through work of art.

Zurich's evolution museum hosts a unique collection of skeletons among its natural history treasures.

This eclectic architectural gem played witness to Zurich’s colonial past.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.