Where commuters walk through remnants of an ancient Greek necropolis.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.

This spire on an Austrian mountain is wrapped around a long spiral slide and has the world's tallest wooden observation deck.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

The inverted pyramid design of this station stands out amid Bratislava's urban landscape.

Launched by Napoleon's soldiers more than 200 years ago, a cannonball remains embedded in the tower wall.

A sculpture of a beloved local figure, who tipped his top hat to everyone he passed on the streets of Bratislava.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Dedicated to a synagogue that was destroyed after having survived World War II.

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

A diminutive statue that was inspired by the sculptor's own daughter.

Also known as Uncle Karl, the beloved bronze copper keeps a watchful eye on St. Stephen’s Basilica while people rub his lucky belly.

A highly-criticized monument in Budapest has become the site of a makeshift Holocaust memorial.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

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

Breathtaking and huge 430 year old maps of Italy.

This one-time health resort was used by aristocrats around the world.

One of the shortest streets in York has an especially odd name.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.

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

An underground city of salt.