A mosque is a place of worship where congregate Muslims for prayers Commons. The architectural complex is mostly surrounded by one or more towers or minarets , whose number is not limited. The roof is often dome-shaped. It is the top of a minaret that the muezzin (mouadh-dhan) calls to prayer during the adhan . A mosque is a place of worship; it serves as an institution social , educational: it can thus be accompanied by a madrassa , a training center or a university . It also serves as a venue for meetings and social exchanges.