Vienna's underworld of tunnels and subterranean rivers made an iconic appearance in a 1949 Orson Welles film.

A mocking tribute to the past and modern leadership of Prague.

Also known as the Blue Church, the building was consecrated to the daughter of Andrew II.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

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

Mountain where Jesus was first tempted by the Devil.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

The world's oldest known salt mine.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

American soldiers discovered Europe's best one-liner at the end of World War II.

Ride a dragon train into a world of dwarves.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

This Slovakian statue of an emerging sewer worker might just be a bronze peeping tom.

Macabre astrological automaton clock dating to the late 1400s.

The house that took a plunge into the facade of a museum.

An ornate private entrance to the Vienna subway built specifically for the emperor.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

The solemn exterior conceals an opulent interior of this 17th century church.

Apartment complexes built into huge repurposed natural gas tanks.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Dine amidst exotic plants at this former royal greenhouse.