A silly medieval mural preserved on the side of a Viennese house.

Visiting this café is like visiting the Austrian grandma you wish you had.

Op-art architecture designed for happiness.

Physicist’s epitaph provides final confirmation to a career of turmoil.

This building has survived for more than a century and remains virtually untouched.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Beautiful antiques and obscure engineering artifacts trace the evolution of phones from rare luxuries to ubiquitous.

This sculpture honors the man who was known as the "Righteous Among the Nations."

The largest statue of this convex, homogeneous object with just one stable and one unstable equilibrium point.

The metal leaves on this tree are engraved with the names of Holocaust victims.

Budapest's Communist-era statues, banished to the suburbs.

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

This historic black and white monastery is one of Bulgaria's architectural jewels.

Founded in the 4th-century, the town of Pernik plays host to the Surva Carnival⁠—a magnificent display of masked Kukeri dancers.

One of the largest mines in Bulgaria is now home to a vast museum more than 100 feet underground.

This building has two facades of clashing architectural designs.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A striking symbol of the Bulgarian capital.

In the center of Wrocław's old meat market stands a somber tribute to the city's livestock.

This oddly beautiful water cistern is a techno-temple to the wet stuff and a multimedia masterpiece.

A 90-ton, gravity-defiant steam locomotive shoots for the skies in this bizarrely beautiful public artwork.

A striking public sculpture representing the period of martial law in Communist Poland.