Visit JamKaran Mosque near Qom

In 986 AD, a devout Muslim by the name of Hassan ibn Muthlih had a mystical experience in which the Imam al-Mahdi (the Imam of the Ages, and son of the 11th Imam, al-Hasan al-Askari) and the prophet Khizr (the 'Green Sage') appeared to him and directed him to organize the building of a mosque on the holy ground of Jam Karan.