In the summer, the area around this sculpture transforms into a vibrant concert venue.

A national collection of Communist-era musical posters.

A hidden art gallery in an abandoned Warsaw fort.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

An underground city of salt.

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

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Cold war icon and onetime "hole" in the iron curtain.

From Iggy Pop to David Bowie to Nick Cave, this regal music studio has served some of the all time greats.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

Known simply as "The Hand," this famous public sculpture in Berlin was featured in a Depeche Mode music video.

A monument to the man who almost killed Hitler.

Super-heavy Nazi architectural experiment.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

A surreal museum of extraordinary industrial objects.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

A menacing statue of this mythical creature can be seen at the legendary site of the monster's lair.

Warsaw's fantastically preserved gasworks...almost.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

A cave in southern Italy adorned with thousand-year-old Biblical frescoes existed in obscurity until fairly recently.

An Italian hillside ghost town.