An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

The world's only museum devoted to the wonders of fluorescence.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

A giant glider—designed by the father of the Rubik's Cube's designer—now soars within a shopping mall.

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

The true meaning behind this sculpture remains unknown.

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

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

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

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

Some of the greatest minds in the history of Hungarian art and science converged in this café.

This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

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

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

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

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

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

A chemical factory damaged by two earthquakes and an explosion that became abandoned after bankruptcy.