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

This graffitied 19th-century building was a prototype of European industrial architecture.

This striking sculpture of Icarus honors Greece's fallen flyers.

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

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

An ancient octagonal weather station named for the eight Greek gods of wind.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

This grand hydraulic installation has provided water for townspeople since the Middle Ages.

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

The largest salt lake in the Sahara is mysteriously alluring.

An ancient Phoenician citadel once stood at the site where Queen Dido first landed, according to legend.

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.

After 400 years of being closed to the public, this monastery's underground tunnels and secret garden are now a museum.

This garage is frozen in the late 1990s, full of rare and untouched cars and motorcycles.

Dynastic Home of the De Piro Family.

This church is named for one of the most dramatic tales in the early Christian church.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

The floor of this spectacular Baroque sanctuary is covered in memento mori.

Enigmatic tombs and cave dwellings on the outskirts of a rural village.

This unique building in the main square stands out among the city's typically Baroque architecture.

A German shoemaker-turned-folk-hero whose impersonation of a Prussian military officer earned international notoriety.

The official motto of Luxembourg reminds passersby of the Luxembourgish commitment to their national identity and sovereignty.

Healing waters from a holy well, previously used by locals for doing laundry.