Arabic mesjid in Islam, a place of worship. Chief features are: the dome; the minaret, a balconied turret from which the faithful are called to prayer; the mihrab, or prayer niche, in one of the interior walls, showing the direction of the holy city of Mecca; and an open court surrounded by porticoes. The earliest mosques were based on the plan of Christian basilicas, although different influences contributed towards their architectural development. Mosques vary a great deal in style in various parts of the world.