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

Catacombs turned marketplace.

Commonly acknowledged as the only public monument to the Devil himself.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Lady Liberty's original designer installed a little clone in this French fountain.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

The world's largest reflecting pool is just two centimeters deep.

This small group of sand dunes manages to pack in a strange rainbow of colors.

Réunion Island's highest point is a 2 million-year-old volcano and a paraglider's paradise.

Haunting and beautiful trees, doomed to die.

A massive volcanic plug is now a protected area that hosts a number of bird species.

Come for the flowers, stay for the bats!

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

The oldest burial ground in the city, final resting place of city founders, Ohlone natives and murderers alike.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This bridge was constructed from the rubble of the infamous Bastille.

The Sun King's military models, saved from the Louvre.

This museum houses an imposing skeleton army comprised of creatures great and small.

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