The most visited pilgrimage site in Armenia once held a saint in a pit for 13 years.

This Armenian monastery was carved out of cliffs and named after the spear used to stab Jesus.

A geological oddity topped with a 2,000-year-old pagan temple.

Yemen's "Stone Palace" looks like it was carved right out of the tall stone column on which it is built.

One of the most remote and isolated villages on the Arabian Peninsula.

A city built from mud and known as the "Manhattan of the desert."

The most alien-looking place on Earth.

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.

A fountain standing as a testament to a doomed alliance.

The legendary luxury train passage is commemorated with a charming museum inside its former eastern terminus.

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

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

Step back in time and witness the fall of Constantinople.

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

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

This museum was invented in a novel before being made real by the author.

A marvel of Byzantine engineering under the streets of Istanbul.

Roman ruins top white travertine terraces formed by ancient hot springs.

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

Elevated freight railway turned wildly successful urban park.

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

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

The most visited, and possibly most controversial, museum in Germany.

This ancient city—home to nine civilizations—is soon to be buried under 200 feet of water.