A shrine of fire worship built on top of a natural flame.

One of the world's largest salt caves is filled with fragile salt sculptures, salt rivers, and huge salt megadomes.

In the foothills of the lesser Caucasus, a centuries-old fortress still stands.

Azerbaijani ghost town, decaying after a war left it an armed forces buffer zone.

A scenic canyon with thick forests and historic ruins.

Mysterious hillside with a continuously burning natural fire.

Home to nearly a third of the world's mud volcanoes, Azerbaijan is home to a messy, bubbling, and sometimes explosive landscape.

Resonant stone, that has been played since prehistoric times.

This living legend of maritime history is enjoying a second life.

Far from the shore, this sandy victim of the Skeleton Coast looks like it was plopped in the middle of the desert.

A desert that rolls right up to the ocean, where it's so dry animals live off the fog.

This "dead marsh" sits among the largest sand dunes in the world, a forest frozen in time.

Held in a fort that once stood for colonization of the area, this museum now tells the history of its indigenous people.

Ancient artists in the middle of nowhere.

This striking otherworldly landscape outside Angola's capital city is the product of millions of years of erosion.

Abandoned ships along a deserted beach feel like the set of a post-apocalyptic thriller.

Did Gustav Eiffel design this enigmatic metal building?

This horseshoe-shaped waterfall is the second-largest on the African continent.

This moss-covered, rocky outcropping looks like a mythical beast resting in the water.

A vast Communist-era exhibition space in the Bulgarian capital.

Within the Saudi Arabian desert lies a 2,000-year-old ghost town made of stone and mud.

The rocks around this mountain are filled with so many carvings that the area became known as the "open library."

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

An unfinished tomb carved into a giant boulder in the Arabian Desert.