A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A vast Communist-era exhibition space in the Bulgarian capital.

A collection of art from Bulgaria's time as a communist state.

The mountaintop inspiration for Umberto Eco's "The Name of the Rose."

Climb inside an iron crystal magnified 165 billion times its normal size.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A fascinating insight into daily life in the Eastern Bloc.

The most visited, and possibly most controversial, museum in Germany.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

Cozy basement bar sports an inventory of over 2,000 beers.

This strange bovine gargoyle is said to have been put in as a passive aggressive form of revenge.

This private skyway is filled with art and was expanded explicitly so that Hitler could appreciate a river.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

A sulfuric hellscape in southern Italy.

The oldest volcanology research center in the world.

Pompeii's less famous neighbor is still revealing her secrets.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

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

In a city that boasts four separate inclined cable railways, this is one of the busiest funicular lines in the world.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.