The nobah or nawbah of Yemen are cylindrical tower farmhouses that serve as residences and as fortresses. They are the descendants of pre-Islamic and early-Islamic circular stone structures of the region. These farmhouses can be found throughout the province of Sana'a, some having been integrated into the city as it expanded. Some nobah constructed in ashlar masonry still stand as part of palaces of the Imam that ruled the city.

With their cylindrical form, the nobah are structurally very strong. Some even support the popular mafraj, a rectangular parlor for receiving and entertaining visitors at the top story of the house. Like the non-cylindrical tower houses, the first floor of the nobah is reserved for storage. The family living quarters are located above the storage areas.

Sources

Lewcock, Ronald, Paolo Costa, R.B. Serjeant, and Robert Wilson. "The Houses of San'a'." In San'a an Arabian Islamic City, edited by R.B. Serjeant and Ronald Lewcock, 464-465, 468, 485, 488. London: The World of Islam Festival Trust, 1983.

Lewcock, Ronald, R.B. Serjeant, and G. Rex Smith. "The Smaller Mosques in San'a." In San'a': An Arabian Islamic City, edited by R.B. Serjeant and Ronald Lewcock, 386. London: The World of Islam Festival Trust, 1983.

Lewcock, Ronald, Paolo Costa, R.B. Serjeant, and Robert Wilson. "The Urban Development of San'a'." In San'a an Arabian Islamic City, edited by R.B. Serjeant and Ronald Lewcock, 123-138. London: The World of Islam Festival Trust, 1983.