This Polish cave has housed a dragon, a brothel, and an enduring legend.

Extremely famous in his native country, this Cracovian painter is all but unknown beyond Polish borders.

A UFO-shaped event building originally intended to be a science museum showcasing the future.

This colorfully-painted tunnel links two distinct parts of a historic neighborhood.

A nearly 25-foot concrete sculpture of Sylvette, Picasso's muse.

This hotel was once home to a steamliner company and became the final rest stop for Europeans heading to the New World.

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

A modern reimagining of a medieval city gate.

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

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

This lurid German fountain plots the sad course of marriage from dating to death.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

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

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

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

The graveyard is filled with beautiful funerary art and boasts breathtaking views of Florence.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

The largest fountain in Bratislava.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

The body of at least one victim of a construction accident was left behind in the collapsed pylon, buried under tons of concrete.

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