The old observatory in Copenhagen has a spiral corridor used as a racetrack.

One of Scandinavia's largest mosaics pays tribute to Danish art and science luminaries.

This bridge's unique architecture honors nautical heritage and encourages self-awareness.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

Visitors are treated to a stained glass kaleidoscope interior inside this work of art.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

This sublime architectural marvel is a rare example of an expressionist church.

This red light district plaza memorializes the Fab Four and their historic connection to the area.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

This once-derelict building is now one of the most beautiful bookstores in the world.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

The preserved arm of a third-century sorcerer is believed to have the power to lift curses and spells.

Looming communist pillar with a Czech twist.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

This enormous abandoned prison was once dubbed the "Bastille of Romania."

Sofia's legislative center is continuously reinventing itself.

"Holy Wisdom" overlooks the city that became its namesake.

A flamboyant five-story building in Bulgaria resembles a crawling snail.

A collection of art from Bulgaria's time as a communist state.

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

A decaying, yet still functioning, work of communist architecture.

An homage to the medieval rulers of Bulgaria.