A sahn, is a courtyard in Islamic architecture. 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 Sahns.
Almost every historic or traditional mosque has a sahn. The use of the sahn in Middle Eastern countries' mosques was carried on to most Islamic countries' mosque architecture.
Traditional mosque Sahns 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 (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.
My message to the world trying to deconstruct the stereotypes about Islam is that some people don’t know anything about courtyards, they think that courtyards are just a big open space with nothing. But in fact it has a lot of meanings, courtyards are places where people can gather and sit, it is a shelter, a school, a hospital ... a place where people can dialogue, beyond their differences.