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

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

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

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

A striking symbol of the Bulgarian capital.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

"Unity, Creativity, Beauty."

Mysterious standing stone formations looks like a petrified forest.

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

In a long-dry lake bed, these groups of massive stone pillars bear a striking resemblance to clumps of everyone's favorite fungi.

UNESCO-protected ancient burial ground.

A flamboyant five-story building in Bulgaria resembles a crawling snail.

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

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

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

This historic black and white monastery is one of Bulgaria's architectural jewels.

Bizarrely shaped rock formations in northwest Bulgaria come with equally bizarre legends.

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

An abandoned saucer-shaped monument in the Bulgarian mountains.