A silly medieval mural preserved on the side of a Viennese house.

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

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

Dine amidst exotic plants at this former royal greenhouse.

A spherical "micro-nation" in the heart of Vienna.

Handsomely crafted representations of our round planet.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A glimpse into the festive and private lives of medieval Europe.

This Armenian monastery was carved out of cliffs and named after the spear used to stab Jesus.

Home of the unusual art of water puppetry, one of Vietnam's oldest curiosities.

This demon atop the Notre-Dame de Paris looks utterly bored.

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

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

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

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

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

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

Morocco’s modern capital was once a haven for Barbary pirates, who went so far as to establish a republic of their own.

Crumbling necropolis set high above Fez.

One of the most spectacular canyons in the world.

Destruction from Armenia's 1988 earthquake inspired an artist's sculptures of scrap metal.

The world-record holder for the longest bridge stretching continuously over water.

This erect, phallic geological spire wasn't always named so domestically.