A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

A sprawling collection of books and manuscripts about ancient Greece that would have put their famed libraries to shame.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

These ruins in Volvi were once at the intersection of the Eastern and Western Worlds.

A little-known park with unusual, half-ruined structures and a mystical energy.

The giant scales in this museum can still tell if someone is one of the devil's brides just by weight.

An ancient monastery, a locked room, and a mysterious book heist.

1513 Turkish world map, full of European state secrets and snarky commentary.

Dynastic Home of the De Piro Family.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

Mysterious Spanish catacombs of unknown origins.

One of the most well-known city festivals in the world.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

An eerie, derelict amusement park in Berlin.

The abandoned remains of this Victorian brewery hide crumbling bowling alleys and rusting industrial gear.

Super-heavy Nazi architectural experiment.

Berlin's old airport.

One of the largest museums in Ukraine remembers the story of the German-Soviet War in iconic, brutalist style.

A former Latvian headquarters of the brutal KGB secret police is now open as a grim reminder of their atrocities.

When German-Iraqi relations broke down, this embassy was vacated post haste.

Blitzkrieg bop your way through Berlin's Ramones Museum.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

The beautiful baroque library of the Hapsburg empire.

The final resting place for the remains of 143 Habsburg royalty.