The development of the city of Shibam in the sixteenth century is considered by many as one of the oldest and most significant examples of urban planning applying the principle of vertical construction. The city was based on a fortified rectangular layout with narrow streets and large squares.
Several factors contribute to this design. The first is geographical and is closely related to the rains, like those that swept away the homes in the original town: Shibam is located beside a wadi, an Arabic term that refers to a valley or a dry river bed where water only flows in the rainy season. Moving to a higher site allowed the residents to avoid future flooding, but at the same time it greatly limited the space in which they could build.
The second factor is related to defense. Shibam’s design, fortified and full of adjacent houses and narrow streets, is a response to the need to protect it from being attacked by neighboring towns or groups that looted towns in the desert. The homes themselves reflect this: many are connected to each other with walkways so that the occupants can escape in the event of an enemy attack, and most have no windows on the lower floors.
However, the way Shibam was planned was also intended to show its economic and social prestige. For centuries, the city was a major trading center in the region and a strategic point on the incense and spice route that connected Asia and Europe. “As such the old walled city of Shibam and its setting in Wadi Hadramaut constitute an outstanding example of human settlement, land use and city planning,” the UNESCO World Heritage website points out.