"Shibam, which is now a UNESCO World Heritage Site, is known for its distinct architecture.The houses of Shibam are all made out of mud brick and about 500 of them are tower blocks, which rise 5 to 11 stories high,[3] with each floor having one or two rooms.[4] This architectural style was used in order to protect residents from Bedouin attacks.[citation needed] While Shibam has been in existence for an estimated 1,700 years, most of the city's houses originate from the 16th century. "
https://en.wikipedia.org/wiki/Shibam
https://en.wikipedia.org/wiki/Shibam