This unique building in the main square stands out among the city's typically Baroque architecture.

This bustling Italian plaza is built on the ruins of an ancient Roman amphitheater.

The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Fortified medieval tower house with lovely roof garden.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The yawning maw of this pagan visage is said to bite off the hands of liars.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

Petting this mysterious iron monkey supposedly brings good luck.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

A miniature city, once ruled by the Queen of the Netherlands.

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

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

A floating cat sanctuary on an Amsterdam canal.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

A merchant court dedicated to the fictitious King Arthur is heavily adorned with bizarre Renaissance art.

This fairytale inspired, warped building houses restaurants, shops, and a radio station.

This man-made mound monument was built out of soil from all across the Polish empire.

Naturally formed rock city in Poland.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.