When you've got to go, you've got to go.

The field of tiny caves that mark this Chinese cliffside are each their own historic Buddhist temple.

350-foot-high emperor faces in China's Yellow River valley.

The world's biggest pet store.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

Scale model of St. Peter's Cathedral (Rome) in the middle of a small Dutch town.

Rotterdammers' dirty minds gave this Santa a dirty nickname and cursed it to a life of wandering.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

The last bastion of Roman presence north of the Alps looms over a German town.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

Museum deep in the catacombs of St. Michael the Archangel Church is explored by touch, sound, and smell.

A memorial to the murdered Jews of Kaunas.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

Flamboyant architecture from the turn of 20th century.

A stone marker and sculpture in the city of Riga stake a claim for the very first community Christmas tree.

A black cat protests the City Guild in Riga's Old Town.

Live out your childhood construction fantasies in this one-of-a-kind gyrating hotel.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

The only remaining U-boat that is still floating never actually saw any action in World War II.

WWII rocket launchpad in rural Germany and site of operation backfire.

Europe's largest natural bridge has a 19th century royal chateau built into its side.

A unique hanging cable-car navigates through Dresden, the oldest suspension railway in the world.