An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

UNESCO-protected ancient burial ground.

An abandoned saucer-shaped monument in the Bulgarian mountains.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

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

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

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

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.

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