One of the oldest, well-preserved water treatment facilities in all of Europe.

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

The last municipal pneumatic post system in the world was in operation for over 100 years, and may run again.

A saintly relic hidden in a Prague church basement.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

A Jenga-style cylindrical tower of books that appears to go on forever.

This enormous, elaborate tomb looks oddly out of place next to a suburban Edinburgh bowling club.

This ancient temple is set up to take you on a pilgrimage of self.

An unfinished tomb carved into a giant boulder in the Arabian Desert.