A mechanical clock built in 1914, with a rotation of 12 historical figures on its face.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

In the middle of a Vienna square, Roman ruins dating back some 2,000 years are on display.

Baroque celebration of the end of the Great Plague of Vienna.

Legends surround an ancient tree trunk riddled with nails for good luck.

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

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

Macabre astrological automaton clock dating to the late 1400s.

This spooky statue sits outside a famous Prague theater.

A significant example of Czech cubist architecture—a style you won't find anywhere else in the world.

The palace window through which Protestant nobles flung two Catholic regents, thus sparking the Thirty Years' War.

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

A saintly relic hidden in a Prague church basement.

Amsterdam's Red Light District leaves little to the imagination.

After Christopher Columbus died, his son built a fancy house to rule from.

The oldest colonial fortress in the Americas was once the home and later prison of Christopher Columbus.

Built in 1512, the oldest cathedral in the Americas.

The first hospital in the New World.

A remarkable range of flora and fauna are represented in this Dominican nature preserve.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

This fountain is dedicated to the workers who perished constructing the Fréjus Rail Tunnel.

The compass on its front was a handy tool for 17th-century merchants who needed to know the direction of the wind.