The capital city of Yemen, Sana'a is one of the oldest populated cities in the world. Historically, its strategic location has allowed it to control the movement of trading networks, governing access from the Indian Ocean and Mediterranean to the Red Sea ports. Sana'a has been a site rich in Islamic architectural history since the seventh century, when Islam was largely adopted in Yemen. Sana'a's architectural heritage is a culmination of influences and styles; containing elements of Umayyad, Rasulid, and Ottoman architecture. Particular to Sana'a is a vibrant tradition of vernacular architecture, known for its use of carved timber, stone, and stepped masonry in multi-level houses. The western city has historically been the site of palatial architecture, including the notable Ayyubid "Sultan's Garden." Other notable complexes include a number of caravanserais and public hammams. In 1974, legislation required that all new buildings be executed in accordance with the traditional Yemeni styles. In 1986, the old city was declared a UNESCO World Heritage Site. Much of the Old City has since been destroyed, as a result of bombings throughout 2015.
Recipient of the Aga Khan Award for Architecture in 1995.
Since its founding 2,000 years ago, Sana'a has been a major trading centre for south-eastern Arabia. Once a seat of government for the early Islamic caliphs, it is today the capital city of Yemen. Typical houses in Sana'a rise to as many as nine stories. The lower levels are usually built of stone, and the upper ones of lighter brick. The windows are outlined in white gypsum and have fan lights of alabaster or coloured glass held in gypsum tracery. Because the urban expansion of the 1970's and 1980's had begun to threaten and eventually destroy the old city, in 1984 the Republic of Yemen created the General Organisation for the Preservation of Old Sana'a. By 1987, it extended its responsibilities to all of Yemen and became the General Organisation for the Preservation of the Historic Cities of Yemen (GOPHCY). UNESCO and UNDP assisted the preservation planning process, while technical assistance and funding were provided by the Yemeni government and by Germany, Italy, the Netherlands, North Korea, Norway, Switzerland, and the U.S.A. About 50 percent of the city's streets and alleys have been paved with patterned bands of black basalt and white limestone, and the repair continues. Old water supply and drainage systems were upgraded, and craftsmen are restoring the city's mud walls. Numerous buildings dating from the 14th, 17th, and 19th centuries have been restored. The jury notes that "this project has saved old Sana'a."