A sacred lake with thousands of sacred carp and a biblical history.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

Mausoleum and Holy Seat of Antiochus I of Commagene.

A fountain standing as a testament to a doomed alliance.

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

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

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

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

A Turkish monastery tucked into a cliff wall.

Large miniature theme park with 100-plus models.

Roman ruins, natural methane fires and a lovely beach.

Standing proud atop a Turkish bluff, this Ottoman palace has retained its grandeur despite being abandoned for centuries.

The best-preserved ancient theater in the world.

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

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

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

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

Hidden just under the waters around this Turkish island are the ruins of a once great city.

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

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

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

A marvel of Byzantine engineering under the streets of Istanbul.

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

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.