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

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

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

The topiary maze at the Habsburg hunting lodge.

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

Apartment complexes built into huge repurposed natural gas tanks.

A 20-meter (65-foot) robot towers over Tokyo Bay.

This little replica of Lady Liberty provides a bit of NYC in a Japanese city.