This term literally means "thresholds." The Shii shrine cities of Iraq: Najaf, Karbala, Kazimayn, and Samarra-locations of the tombs of the six Imams-are important centers of devotion, pilgrimage, scholarship, and political activism. Pilgrimage to these tombs, especially Karbala, is considered desirable, and these cities remain places of Shia scholarship today.