Underground monastery and fortress.

Foreign invaders almost left this lovely Caucasus palace alone—almost.

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

A gigantic collection of teeny, tiny books.

Resonant stone, that has been played since prehistoric times.

Mysterious hillside with a continuously burning natural fire.

Feed it cash, get your very own gold bar.

The largest falcon hospital in the world, caring for over 6,000 feathered patients every year.

This enormous sports car themed amusement park is home to the world’s fastest roller coaster.

This indoor ski resort has a mountain contained inside a mall.

This artificial archipelago was supposed to resemble a map of the world.

Planned as the world’s first zero-carbon city, it had lofty ideals—but is only 5 percent completed and aiming for 50 percent carbon-neutral.

Over the dunes of the Empty Quarter, the mysterious music of the desert.

Whitewashed mosque contains the world's largest carpet.

Billed as the "largest natural flower garden in the world" this Middle Eastern show field has little competition at 45 million flowers.

Yemen's "Stone Palace" looks like it was carved right out of the tall stone column on which it is built.

A mesmerizing reservoir nestled at the heart of a pre-Islamic Yemeni village.

The most alien-looking place on Earth.

This bazaar is one of the oldest in the Arabian world.

An imposing Omani fortress surrounded by date palm trees.

A sinkhole and now a swimming hole, too, full of dazzling turquoise water.

An archaeological site believed to be the burial place of the "mother of us all."

Village of slate houses, built on a white marble outcrop.

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