In Egypt's expanding metro area, many of the neighbors are dead.

An underground network of massive stone arches and their skylit vaults support ruins of portico structures above.

These ruins once flourished as the capital of the Lydian kingdom, often credited with the invention of metal coinage.

The ancient latrines of the Greeks, in all their public glory.

Ancient serpentine sacrifice holder that has stood the test of time.

The largest Neolithic ruins in the world hide a notably clean prehistoric metropolis.

The best-preserved ancient theater in the world.

1513 Turkish world map, full of European state secrets and snarky commentary.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

Naturally protected city carved from a rock face.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

An abused and forgotten metropolis, abandoned for centuries.

This famous city eluded concrete detection until the early 2000's.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

A marvel of Byzantine engineering under the streets of Istanbul.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

This deconsecrated church has seen many uses, from a tobacco storehouse to a cinema.

According to tradition this is the oldest church in Venice, but its actual age is a mystery.

The only museum with its curator—and her pets—buried inside.

Stare out over the lagoon and beyond from this 10th-century campanile on the island where the city of Venice began.

This Roman statue is missing a limb from when the Venetians stole it from Constantinople during the Crusades.