A popular legend claims that the famous pizza was invented at a restaurant in this alley.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

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

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

This column celebrates Rome's victory over the Goths, and may be the oldest Roman monument in Istanbul.

A sixth-century Byzantine cistern hidden below a modern carpet store.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

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

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

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

A marvel of Byzantine engineering under the streets of Istanbul.

This small island off Lambert's Bay is home to more than 2,000 Cape gannets and is the only such breeding colony open to the public.

The original goat tower, the one that started it all.

Despite many attempts to finish this overpass, it has been abandoned since the 1970s.

A sobering account of the vibrant multicultural neighborhood that was destroyed under apartheid.

Formerly known as the Malay Quarter, Bo Kaap is a colorfully-painted suburb located in the “Mother City” of South Africa.

This African beach is home to thousands of rare mainland penguins that are known for their annoying voice.

The remains of a 1st-century aristocratic Roman town house featuring beautiful well-preserved mosaics.

The other side is actually green.