This unreal Portuguese palace looks as though it's made from a pile of different castles.

If you can look past the nearby sewer pipes, this urban sinkhole grotto is a mini-paradise.

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

Pilgrimage site for star-crossed lovers.

Largest illuminated advertisement sign in the world.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

The most visited, and possibly most controversial, museum in Germany.

A fascinating insight into daily life in the Eastern Bloc.

The most famous location in China was home to whole dynasties worth of imperial rulers.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

A musical instrument played by the sea.

A marvel of Byzantine engineering under the streets of Istanbul.

A "miracle" that seems to produce more holy fistfights than holy revelations.

Museum dedicated to the terror regimes of Hungary.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A giant bug impaled on a 75-foot-tall needle.

Meet the bronze beloved pet to a family of famous peeing statues.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

Cozy basement bar sports an inventory of over 2,000 beers.

Petting this mysterious iron monkey supposedly brings good luck.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Lavish royal estate punctuated with heated greenhouses.

The modern birthplace of Irish freedom.

One of Ireland's most infamous prisons for rebels including men, women and children.