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

An abused and forgotten metropolis, abandoned for centuries.

A marvel of Byzantine engineering under the streets of Istanbul.

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

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

A preserved oasis with traditional Andalusian-style architecture and beautiful views of the Nile.

The massive cave church of Cairo's Zabbaleen community is one of the largest Christian churches in the Middle East.

Known as the Sistine Chapel of Egypt, this tomb houses some of the most well-preserved paintings in Egypt.

An abandoned outdoor movie theater in the Sinai desert.

These Egyptian statues have survived for 3,400 years and were an acoustic wonder of the ancient world.

One of the most well-preserved temples of ancient Egypt.

Ozymandias’ time-keeping temple.

An ancient city exhumed from the depths of the ocean.

The oldest operating pharmacy in the world features 800-year-old recipes.

The underground sanctuary of a mysterious ancient cult.

Pompeii's less famous neighbor is still revealing her secrets.

A submerged archeological park still holds the wonders of a Roman Sodom.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

Hidden in a secluded Greek cove is a pristine beach marred only by the rusting smuggler's hulk stranded on its shores.

The remains of what was, not so long ago, the world's largest city.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Once an indicator of social class, the color blue has come to define this city on the edge of the Thar Desert.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.