This mysterious abandoned fort looks like something pulled right from Arabian legend.

Traditional architecture and ancient irrigation systems are on display in this gorgeous mountain village.

Nature's water park in the Wadi Bani Awf valley is full of pools flanked with cliffs and natural water slides.

An imposing Omani fortress surrounded by date palm trees.

This spectacular mosque houses the second-largest chandelier in the world.

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

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

This giant underground cave chamber can only be accessed through a small opening at the top.

A section of the desert with an array of unusual sandstone and limestone formations.

A powerful cyclone once made one of the world's largest sinkholes completely fill with water.

These gnarly desert trees produce the prized aromatic resin traded along the ancient incense trail.

The tallest minaret in Yemen is 150 feet high and entirely made of mud.

A city built from mud and known as the "Manhattan of the desert."

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

One of the most remote and isolated villages on the Arabian Peninsula.

Take a ride back in time with a steam locomotive trip through Eritrea’s mountainous countryside.

Scrap material from around Eritrea finds a new life at this outdoor market, where upcycling is a lifestyle.

Wander among hulking piles of rusted machinery left over from the Eritrean-Ethiopian War.

Supposedly this Ethiopian chapel holds the Ark of the Covenant, guarded by virgins who cannot leave the building.

Reaching the "Church in the Sky" requires scaling the cliff face of a sandstone pinnacle with a 650-foot drop.

An otherworldly restaurant perched on the edge of a jagged cliff next to a medieval holy city.

The hottest place on the planet.

The Earth's saltiest natural body of water belches toxic gas.

Ethiopia's "smoking mountain" is in one of the hottest regions on the planet and is home to two lava lakes.