Islamic architecture originated in the 7th century AD during the Islamic conquests. Some key characteristics include courtyards surrounded by arcades, minarets for the call to prayer, and mihrabs indicating the direction of Mecca. Important early examples include the Dome of the Rock in Jerusalem and the Great Mosque of Damascus with its intricate mosaic walls. Over time, regional styles developed like the hypostyle mosques of Iraq and the double-tiered arches of the Great Mosque of Cordoba in Spain. Mosques remain centers of worship and community in Islamic cultures.