The monument honors the first (and for a long time, only) African-born philosopher to teach at a German university.

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

This building has two facades of clashing architectural designs.

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

"Unity, Creativity, Beauty."

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

A striking symbol of the Bulgarian capital.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

Sofia's legislative center is continuously reinventing itself.

"Holy Wisdom" overlooks the city that became its namesake.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

A decaying, yet still functioning, work of communist architecture.

An homage to the medieval rulers of Bulgaria.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

Rock carving created 1,300 years ago 75 feet off the ground.

This once-grandiose behemoth of a monument from the socialist era now sits quiet and closed up.

Mysterious standing stone formations looks like a petrified forest.

An abandoned saucer-shaped monument in the Bulgarian mountains.

This massive stone and steel monument remembers a century-old battle that cost thousands of lives and nearly destroyed the city.

Said to be the only museum in the world dedicated to the most classic of all blooms, the rose.

The remarkably well-preserved final resting place of a powerful ancient Thracian king.

A gigantic statue of a Russian soldier watches over the ancient city of Plovdiv, a prominent reminder of the Soviet period in Bulgaria.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.