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

Op-art architecture designed for happiness.

A spherical "micro-nation" in the heart of Vienna.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

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

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

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

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

The remains of an entire Roman city can be explored in this interactive museum.

The abandoned military base looks like a post-apocalyptic wasteland.

A collection of intricate sculptures so small they have to be seen through a microscope.

These fly sculptures are scattered around the city and represent the patron saint of Girona.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

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

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

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

This subterranean studio is filled with fascinating kinetic art.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

A beautiful maze marks where three countries meet.

Inspired by "The Starry Night" this Dutch bike path turns into a glowing work of art each night.