The largest catacomb system in the world.

In a quiet north Chicago neighborhood rests a stunning relic of the golden age of earthenware design.

An outdoor urban gallery of large-scale artworks by the world's most influential street artists.

A lush green oasis in the middle of Chicago.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

North America's oldest authentic African Village.

Known as "The Hill of the Little Devils."

What might be the largest completely Jewish town in the world outside of Israel now faces dwindling numbers and empty streets.

Founded in the 4th-century, the town of Pernik plays host to the Surva Carnival⁠—a magnificent display of masked Kukeri dancers.

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

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

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

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.

A striking symbol of the Bulgarian capital.

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

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

This historic black and white monastery is one of Bulgaria's architectural jewels.

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

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

This extraordinary, multi-pillared monument depicts the fascinating history of Georgia.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

You'll find just about anything in this funky Tbilisi flea market.

The last standing example of an ancient district's teatime tradition.