The Imam Reza shrine in Mashhad, Iran is a complex which contains the mausoleum of Imam Reza, the eighth Imam of Twelver Shiites. It is the largest mosque in the world by area. Also contained within the complex are the Goharshad Mosque, a museum, a library, four seminaries, a cemetery, the Razavi University of Islamic Sciences, a dining hall for pilgrims, vast prayer halls, and other buildings.
The complex is one of the tourism centers in Iran and has been described as "the heart of the Shia Iran" with 12 million Iranian and non-Iranian Shias visiting the shrine each year, according to a 2007 estimate. The complex is managed by Astan Quds Razavi Foundation currently headed by a prominent Iranian cleric, Seyyed Ebrahim Raisi.
The shrine itself covers an area of 267,079m2 while the seven courtyards which surround it cover an area of 331,578m2 - totaling 598,657 m2 (6,443,890 sq ft). Every year the ceremony of Dust Clearing is celebrated in the Imam Reza shrine.