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

Once an opulent Art Nouveau hotspot, the Constanța Casino is one of Romania's most beautiful abandoned buildings.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

At this archaeological site, visitors can explore the ruins of the capital of the former Roman province of Moesia.

A museum dedicated to the former country.

Legend has it fairies gathered at the site of this medieval castle.

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

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

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

An abandoned saucer-shaped monument in the Bulgarian mountains.

UNESCO-protected ancient burial ground.

This apartment is a true time capsule of local life in Bulgaria during the Soviet regime.

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

A settlement that was stopped in the middle of construction, leaving behind paved roads, curbs, light poles, a stormwater drainage system, and even a basketball court, but no houses.

This open air archeological site houses almost as much wildlife as it does classical religious artifacts.

The abandoned summer estate of the former Greek Royal Family.

A closer look at this somewhat faded hotel by the Corinth Canal reveals the architectural undertones of a genius.

This 15th-century island fortress later served as home to the executioners no one wanted to live near.

The ruins of an abandoned medieval city where the last Byzantine emperor was crowned.

This remarkable cave was discovered after a shepherd watched bees enter and exit through a small fissure.

The historic tower houses of this nearly abandoned Greek town have been compared to the spikes on an iguana's back.

This town named for the ancient God of War is home to fewer than a thousand people, but it's the birthplace of the Greek Revolution.

This quaint farm in the Peloponnese countryside hides an astonishing cache of antique curiosities.

The hallucinogenic center of the ancient world.