The city of Shibam (Hadhramawt) stands on a rock in the middle of the Wadî. Ramparts enclose a trapezoidal shaped area measuring 380 by 250 m . Inside, there are about 500 high-rise houses built in mud-brick , the palace of the Quayti Sultan and some mosques, all built in the 19th and early 20th cent. The paper shows different types of mud architecture in the cities of Tarîm, Huraydah, Say'ûn, etc. The city of Shibam is on the list of the World National Heritage.