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

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

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

The ancient latrines of the Greeks, in all their public glory.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

Found art has transformed this Pittsburgh neighborhood into a psychedelic dream.

The only way to see Pittsburgh is from the top of this lookout point, just like the ancient members of the native peoples did.

There aren't too many operational funiculars around, but Pittsburgh has two!

One of the steepest streets in the United States makes an intriguing challenge for cyclists.

A full-size replica of this well-preserved temple lets you take a walk through the Mayan age.

This staircase full of Mayan hieroglyphics is perhaps the largest single text in the world.