Beneath a Virginia City bar is the entrance to an abandoned gold mine.

Singing sand that stands as the final remains of an ancient lake.

This Old West eatery along America's Loneliest Road was originally a stop on the Pony Express.

A towering tribute to decisiveness stands on the spot where Brigham Young and his followers decided that this must be the place.

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

A museum glorifying the life of Stalin, located in the city of his birth.

Fortified homes of highland warriors that are still in use today.

God's Saharan sandbox of wrath.

Crumbling necropolis set high above Fez.

Traditional 11th-century outdoor tannery.

The other side is actually green.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Founded as a refugee camp, now a popular tourist spot.

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

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

A fountain standing as a testament to a doomed alliance.

A marvel of Byzantine engineering under the streets of Istanbul.

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

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

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

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

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