Mosque

A mosque or masjid is a place of prayer for Muslims. Mosques are usually covered buildings, but can be any place where prayers are performed, including outdoor courtyards.The first mosques were simple places of prayer for Muslims, and may have been open spaces rather than buildings. In the first stage of Islamic architecture, 650-750 CE, early mosques comprised open and closed covered spaces enclosed by walls, often with minarets from which calls to prayer were issued. Mosque buildings typically contain an ornamental niche set into the wall that indicates the direction of Mecca and ablution facilities.

Source: Wikipedia