Shibam bears witness to the cultural identity of the people of Wadi Hadramaut and their former traditional way of life. The dense layout of Shibam surrounded by contiguous tower houses within the outer walls expressed an urban response to the need for refuge and protection by rival families, as well as their economic and political prestige. As such the old walled city of Shibam and its setting in Wadi Hadramaut constitutes an outstanding example of human settlement, land use and city planning. The domestic architecture of Shibam including its visual impact rising out of the flood plain of the wadi, functional design, materials and construction techniques is an outstanding but extremely vulnerable expression of Arab and Muslim traditional culture.