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

"Unity, Creativity, Beauty."

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

Eastern Bloc nostalgia, anybody?

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

Outstanding, eerie frescoes and decorations fill this 19th-century monastery.

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

UNESCO-protected ancient burial ground.

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

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

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

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

A striking symbol of the Bulgarian capital.

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

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

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

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

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

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

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

An abandoned saucer-shaped monument in the Bulgarian mountains.

According to a gruesome legend, an architect sacrificed his wife to build this spectacular, 16th-century cathedral.

This fortress-like monastery is covered with intricate frescoes.

Visit an imposing 13th-century Transylvanian citadel lurking not far from the region's more heavily touristed attractions.