The Manhattan of the desert

Shibam, Yemen is home to some of the oldest skyscrapers in the world. Some of them date back over 500 years. The houses of Shibam are all made out of mud bricks. There are about 500 surviving tower houses, rising 5 to 9 stories high. the city has been in existence for about 2,000 years. But most of the city's houses come mainly from the 16th century.
The city was first settled as a result of ancient incense trade routes. Later it became the capital of the Hadramawt under Islamic rule. Because of it's location on an elevated piece of ground in the river floodplain, and a desire of it's inhabitants to live within a protective wall, houses were built vertically.

Via DeputyDog: the world’s first skyscrapers