A line of disused military bunkers built to defend against Nazi invasion lies hidden on the outskirts of the city.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

The largest fountain in Bratislava.

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

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

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.

A unique hotel for the artistic soul.

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

Museum devoted to the artificial language of Esperanto.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

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

Apartment complexes built into huge repurposed natural gas tanks.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

This cubist Vienna church building looks like some sort of alien stonehenge.

The resting place for anonymous victims of the Danube's dark waters.

Op-art architecture designed for happiness.

Located right outside of Vienna, visitors can take in expansive views of an ethereal forest.

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

This former insane asylum now holds a pathological anatomy museum.

Handsomely crafted representations of our round planet.

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

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Its town washed away centuries ago, this lonely tower by the sea tells the tale of a mermaid and a curse.