Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

Gargantuan home of Russian science.

Stalinist skyscraper built with help of cryotechnology.

The tallest hotel in Europe.

Former headquarters of the KGB.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

An eerie, little-known Neapolitan museum filled with preserved human remains.

This shining multicolored metro station deep under Naples is said to be the most beautiful in Europe.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

This giant middle finger statue sends an unambiguous message to Italy's bankers.

Deliberately hidden for centuries, the magnificent Saadian Tombs were eventually uncovered in 1917.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

It took 40 years to build this Eden-like garden in Marrakech, later restored by Yves Saint-Laurent.

This vast masterpiece of Moroccan architecture spreads across 20 acres.

A whimsical bridge adorned with decorative dragons.

Dozens of elegant ceramic tiles decorate these ancient walls, each displaying the Lord's Prayer in a different language.

An Art Nouveau building covered in animal gargoyles and grotesques.

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