Some believe this abandoned Brutalist masterpiece inspired George Lucas's Sandcrawler.

The ancient heart of Tunis is an enormous maze of narrow streets and alleyways.

The best-preserved Roman small town in North Africa.

An ancient burial ground believed to have been used for ritual sacrifice.

An underground city of salt.

This stone tower was built to protect Crete from incoming pirates.

Τhis feline monument commemorates fallen soldiers on a field that saw many, many battles.

This 18th-century former mosque held the first Hellenic Parliament.

These ancient ruins hide in plain sight next to a dessert shop.

Only open for two days a year, this church links ancient Greek and modern Christian celebrations.

Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

The only ancient site that remains on the south bank of the sacred Ilissos river.

An intricate network of underground tombs carved into volcanic rock.

View the ancient remains of buildings and the ancient "River of Hades" before hopping on a train.

This "volcanic all-day restaurant" is right on the beach.

This abandoned shopping arcade has new life as an art installation.

According to legend, this cavern holds the passage that Persephone used to travel to and from the underworld.

These caves secretly held national treasures during World War II.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

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

This gem is often wrongly overshadowed by the larger, newer Metropolis church in Athens.

Gladiators once walked this ancient, subterranean passage.

Replicas of Apollo's leonine stone guard cats still line a sacred row in Greece.

Giant marble phalluses on the sacred island of antiquity.