Imām Reza shrine (Persian: حرم امام رضا) in Mashhad, Iran is a complex which contains the mausoleum of Imam Reza, the eighth Imām of Twelver Shi'ites. It is the second largest mosque in the world. Also contained within the complex include: 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.
In 818 Imam Reza was martyred by Al-Ma'mun and was buried beside the grave of Harun. After this event this place was called as Mashhad al-Rida (the place of martyrdom of Ali al-Rida). Shias and sunnis started visiting there for pilgrimage of his grave. By the end of the 9th century a dome was built on the grave and many buildings and Bazaars sprang up around it. During more than a millennium it has been devastated and reconstructed several times.
In 993 the holy shrine was ruined by Saboktakin, a Ghaznavid king. However in 1009 his son Sultan Mahmood Ghaznavi ordered the shrine to be repaired and expanded. About 1150 Sultan Sanjar, a Seljuq king, renovated the sanctuary and added new buildings after miraculous healing of his son in the shrine. Later Sultan Muhammad Khodabande, an Ilkhanate king, who converted to Shiism renovated the holy shrine about 1310. The celebrated Muslim traveler Ibn Battuta visited Mashhad in 1333 and reported that it was a large town with abundant fruit trees, streams and mills. A great dome of elegant construction surmounts the noble mausoleum, the walls being decorated with colored tiles. Opposite the tomb of the Imam is the tomb of Caliph Harun al-Rashid, which is surmounted by a platform bearing chandeliers.
In the 15th century, during the Shahrokh era, it became one of the main cities of the Timurid dynasty. In 1418 his wife Goharshad funded the construction of an outstanding mosque beside the shrine, which is known as the Goharshad Mosque.The shrine is depicted on the reverse of the Iranian 100 rials coin, issued since 2004.