An ancient Egyptian temple in the middle of Madrid, Spain.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Within the Saudi Arabian desert lies a 2,000-year-old ghost town made of stone and mud.

An unfinished tomb carved into a giant boulder in the Arabian Desert.

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

For centuries, Jeddah’s old town was a major trading port and a point of entry for Hajj pilgrims traveling by sea.

Breathtaking and huge 430 year old maps of Italy.

The Pope’s secret escape route.

A treasure trove of Renaissance-era funerary art in a Roman church built on top of Nero's grave.

The remains of this 2nd-century Roman temple are incorporated into a modern building.

This ancient market is often referred to as the oldest shopping mall in the world.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This curious, round temple is the oldest still-standing marble building in Rome.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

A dead saint, a deadly poison, and a mysterious holy ooze.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

A medieval setting reimagined into a unique art alley.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.