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

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

A unique hotel for the artistic soul.

In the fictional world of Kcymaerxthaere, standing at this site just outside Vienna, Austria, the sky would have been found beneath your feet.

Apartment complexes built into huge repurposed natural gas tanks.

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

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

Baroque celebration of the end of the Great Plague of Vienna.

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

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

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

The topiary maze at the Habsburg hunting lodge.

This former insane asylum now holds a pathological anatomy museum.

Amsterdam's former hotspot for public executions and dissections.

A floating cat sanctuary on an Amsterdam canal.