Ruins of an early Roman Christian church dating back to the 4th to 5th centuries.

An unfinished complex built for children from around the world sits abandoned on the Black Sea coastline.

A mountain pass in Bulgaria's Balkan Mountains was the site of four historic battles.

"Unity, Creativity, Beauty."

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

Mysterious standing stone formations looks like a petrified forest.

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

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

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

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.

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

An abandoned saucer-shaped monument in the Bulgarian mountains.