Jamkaran is a village in Qanavat Rural District, in the Central District of Qom County, Qom Province, Iran. Jamkaran is located on the outskirts of Qom, and is the site of the Jamkaran Mosque, a popular pilgrimage site for Shia Muslims from all over the world. Shia belief has it that Imam al-Mahdi—the Twelfth Imam, a Shia figure will lead the world to an era of universal peace — once appeared and offered prayers at Jamkaran. On Tuesday evenings large crowds of thousands gather at Jamkaran to pray.
The mosque, six kilometres east of Qom, has long been a sacred place, at least since 373 A.H., 17th of Ramadan (22 February 984 C.E.), when according to the mosque website, one Sheikh Hassan ibn Muthlih Jamkarani is reported to have met Imam al-Mahdi.
Jamkarani was instructed that the land they were on was "noble" and that the owner — Hasan bin Muslim — was to cease cultivating it and finance the building of a mosque on it from the earnings he had accumulated from farming the land.
Tuesday is especially popular as it is said to be "the day the vision appeared and therefore the day of the week that [the Imam], although invisible, takes requests." The gathering "resemble a huge tailgate party where vendors set up in the parking lots and families set up picnic rugs and tens of thousands wander about the grounds as if waiting for a main event to happen." More than a hundred thousand pilgrims sometimes pray outside the overflowing mosque for Maghrib prayer. In keeping with separation of the sexes, women are separated from men in their own special cordoned-off area and also have their own well. Also on Tuesdays, the mosque kitchen provides a free evening meal to thousands of poor people. There is a significant body of Shia writing arguing that the Imam Mahdi is hidden but active in the world helping those who are needy.