These artifacts were discovered during the construction of the airport, with some dating back to the Neolithic period.

Where commuters walk through remnants of an ancient Greek necropolis.

Heralded as the world's first theater, these ruins are often overlooked as they reside in the shadows of the Acropolis.

The Cycladic architecture makes this Athens neighborhood feel like an island paradise hidden in the shadow of the Acropolis.

Legend says this sacred tree was a gift from goddess Athena.

Created as a "model concentration camp" to hide Nazi atrocities from the international community, this former camp-ghetto now holds a museum and memorial honoring the lives lost within.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

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

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

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

At this 16th-century monastery in rural Bulgaria, visitors can also spend the night.

A decaying, yet still functioning, work of communist architecture.

This massive stone and steel monument remembers a century-old battle that cost thousands of lives and nearly destroyed the city.

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

An abandoned saucer-shaped monument in the Bulgarian mountains.

One of the most poignant ruins of the Chornobyl nuclear disaster, the local football team's stadium has been quickly reclaimed by nature.

This attraction was abandoned after the Chornobyl disaster.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

The dining hall that nourishes workers in Chornobyl's Exclusion Zone is also open to visitors.

This derelict superstructure was a very important warning system for the Soviet military.

Marvel at the excessive luxury of the ousted Ukrainian president's former estate.

This unassuming museum's slogan translates to “there is a limit of sadness, anxiety has no limits."

The deepest metro station in the world.