A sahn (, ), is a courtyard in Islamic architecture, especially the formal courtyard of a mosque. Most traditional mosques have a large central sahn, which is surrounded by a riwaq or arcade on all sides. In traditional Islamic design, residences and neighborhoods can have private sahn courtyards. The sahn is a common element in religious buildings and residences throughout the Muslim world, used in urban and rural settings. The cloister is its equivalent in European medieval architecture and its religious buildings. Etymology The word Sahn (صَحْن) means a courtyard in Arabic. History Originally, the sahn was used for dwellings, as a secure and private setting within a residence compound's walls. Ruins of houses in Sumerian Ur with have been found, from the Third Dynasty of Ur (2100–2000 BCE). Most mosque courtyards (sahn) contained a public fountain where Muslims performed Wudu a ritual purification required before prayer. The Great Umayyad Mosque of Damascus built in 706 CE provides one of the earliest withstanding example of a Sahn. The 122.5 meter long and 50 meter wide rectangular courtyard of the mosque is surrounded by a colonnaded portico (riwaq) on three sides. The use of sahn in Islamic architecture continued until the mid-twentieth century, when Modern architecture began to influence Islamic cultures' residential and public buildings' designs. Types Mosque design Almost every historic or traditional mosque has a sahn. The use of it in Middle Eastern countries' mosques was carried on to most Islamic countries' mosque architecture. Traditional mosque are surrounded by the riwaq arcade on all sides. They also contain fountain water basins, such as a howz, for ritual purification cleansing and performing of wudu (Islamic ablutions), and flowing fountains for drinking water. The inner courtyard is not a religiously proscribed architectural feature, and some mosques, especially since the twentieth century, do not have a sahn. Residential design Residential , part of a courtyard house, are the most private. The scale and design details differ: from urban to rural locales; different regions and climates, and different eras and cultures – but the basic function of security and privacy remain the same. The sahn can be a private garden, a service yard, and a summer season outdoor living room for the family or entertaining. Usually the main entrance of the house does not lead directly to the sahn. It is reached through a broken or curved corridor called a majaz (, ).