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

An abandoned saucer-shaped monument in the Bulgarian mountains.

Depending on the region's rainfall, this church may be partially submerged.

It's unclear what caused the fire that led to this opulent hotel's demise.

This fortress dates back to the 6th century and is also the site of a controversial abandoned restoration project.

A solar-powered primary school inspires hope and experimentation in a country ripe for energy innovation.

An abandoned resort in North Macedonia is a relic from the Communist Party of Yugoslavia.

Stone pillars and a petrified wedding party in the hills of North Macedonia.

This 3,800-year-old site contains markers used to study the movement of the sun and moon and create a lunar calendar.

Space-age monument to an early 20th-century uprising.

The final resting place of one of the first alleged vampires.

This spa park features an open-air museum of abstract marble sculptures.

Once a bridge over the River Begej, now high and dry.

A Museum with a collection of 40,000 matchboxes.

This natural spa is known for its healing properties and vibrant hue.

This ice cream parlor serves scoops of flavors like rakia, medlar, and poppy seed.

Once a beautiful palace, this structure is now known as the ''museum of destruction."

This fresco inside a Serbian cave church has been a source of disagreement.

A museum dedicated to the former country.

Stone age urban planning.

An eerie, protected forest of old-growth oak trees, many of which are now dead.

The ridged layers that make up this river canyon represent Earth's geological history.