Built in the 16th century and surrounded by military defensive walls, the ancient castle of Shibam is one of the oldest and most outstanding examples of urban planning based on vertical building rules. The ancient city was built on a cliff face and its impressive tower-like architecture gave the city its name "Manhattan in the desert".
The 16th-century city of Shibham, a city of towering towers made of sun-dried mud bricks, rising from the edge of the cliffs of the Hadramao Valley, is known as the "Manhattan" or "Chicago" of the desert. Situated on the southern plateau of the Arabian Peninsula, an important caravanserai on the spice and frankincense routes, the city consisted of seven-storey dwellings built according to a fortified rectangular grid of streets and squares. The city was built on a rocky hill hundreds of meters above the riverbed, replacing an earlier settlement that had been destroyed by a catastrophic flood in 1532-3. Friday mosques were mainly built in the 9th-10th centuries and the citadel in the 13th century, but the earliest settlements date back to the pre-Islamic period. In 300 AD, after the destruction of the earlier capital of Shabwa, located further west of the valley, Shibam became the capital of Hadramo. In the late 19th century, merchants returning from Asia rebuilt the ancient city, after which the city expanded to the south bank of the valley to form the new suburb of Al-Sahil. The abandonment of the old agricultural flood management system in the river valley, the overload of the traditional sanitation system due to the introduction of a modern water supply system, and poor drainage, combined with changes in livestock management, all contributed to the decline of the city.
The dense layout of the city of Shibam, surrounded by adjoining towers within the outer walls, reflects the city's response to the needs of rival families seeking refuge and protection, as well as its economic and political prestige. Thus, the ancient city of Shibam and its setting in the Hadramao Valley constitute an outstanding example of human settlement, land use, and urban planning. The vernacular architecture of Shibam, including its visual impact, functional design, materials, and construction techniques rising from the floodplains of the river valley, is a remarkable yet extremely fragile expression of traditional Arab and Muslim cultures.
Flood-irrigated land in the surrounding landscape was and is still used for agriculture, forming an integrated economic system involving flood agriculture, mud generation, and the use of mud in building construction, a system that no longer exists elsewhere in the region.