The ruins of an ancient Zoroastrian Tower of Silence believed to be the earliest example of the traditional funerary practice.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

The Avenue of Mausolea is a series of grand palatial tombs.

A cave covered with bizarre stalactites of cloth.

An eccentric dictator's take on a Turkmen version of Disneyland.

A fiery crater has been burning in the Karakum Desert since 1971.

A common entry point to the Griffith Observatory trail holds its own wonders.

This “living museum” at UCLA exhibits thousands of plant species from all over the world.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

Abandoned silver mine strewn with wrecked and twisted structures.

The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Granite outcropping that the state's tourism bureau doesn't promote because of its delicate ecosystem.

Yugoslavia's biggest underground airport lies in ruins.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Legends of treasure and spirits flow from this this fairy tale-like oasis.

Camels and crocodiles share the black waters of this stunning Saharan oasis.

Site of the largest volcanic eruption in the last 25 million years, one which may have nearly wiped out humanity altogether.

The abandoned site of the Beatles spiritual awakening and subsequent revolt.

The small cliffside monastery known as the Tiger's Nest is said to be the meditation site of an eighth-century Buddhist master.

A historic observatory precariously perched at the "Top of Europe."

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Made from local Irish moss, this pie is served only in Prince Edward Island's potato museum.

The pharmacy's retro ice cream mixer is one of the last of its kind.