Holy Shrine of Imam Reza
The shrine complex of Imam Riza (AS) was developed on the site of the eighth Imam's tomb, in what was at the time of his death in 817 the small village of Sanabad. In the tenth century the town acquired the name Mashhad, 'Place of Martyrdom' (used for any burial place of a Muslim martyr),

 

The shrine complex of Imam Riza (AS) was developed on the site of the eighth Imam's tomb, in what was at the time of his death in 817 the small village of Sanabad. In the tenth century the town acquired the name Mashhad, 'Place of Martyrdom' (used for any burial place of a Muslim martyr), and became the most sacred site in Persia. Although the earliest dated structure bears an inscription from the early fifteenth century, historical references indicate buildings on the site prior to the Seljuk period, and a dome by the early thirteenth century. Following periods of alternating destruction and reconstruction, including the sporadic interest of Seljuk and Il-Khan Sultans, the largest period of construction took place under the Timurids and Safavids. The site received substantial royal patronage from the son of Timur, Shah Rukh, and his wife Gawhar Shad and the Safavid Shahs Tahmasp, Abbas and Nader Shah. Under the rule of the Islamic Revolution, the shrine has been expanded with new courts (Sahn-e Khomeini, Sahn-e Jumhuriyet Islamiye), a library and an Islamic university.
This expansion in effect reverses the 'beautification' project of Pahlavi Shahs Riza and Muhammed Riza, in which all structures adjacent to the shrine complex were cleared to form a large green lawn and circular boulevard, isolating the shrine from its urban context. The tomb chamber is located underneath a golden dome, with elements dating back to the twelfth century.   The chamberis decorated with a tile work dado dating from 612/1215, above which the wall surfaces and a muqarnas dome were executed in mirror work in the nineteenth century. Shah Tahmasp gold-plated the tomb dome, which was previously decorated with tile. The gold of the dome was lost to Ozbeg raiders and subsequently replaced by Shah Abbas I during his renovation project begun in 1601. Various other chambers surround the tomb, including the Dar al-Siyada and Dar al-Huffaz, both commissioned by Gawhar Shad. These two chambers provide transition between the tomb chamber and her congregational mosque, situated on the southwest side of the complex. People considers the domed chamber of Allahvardi Khan as probably 'the most perfect component of the shrine'.
 Lying to the east of the tomb, this octagonal chamber is articulated in two stories with bays, arches and galleries, affecting a modeled interior in deep relief. All surfaces are covered in the finest of Safavid tile mosaic, including the muqarnas-filled dome. The assemblage of courts and buildings encircling the inner chambers includes the Mosque of Gawhar Shad, the Madrasa Do Dar, the Sahn-e Engelab or Sahn-e Atiq (the old courtyard), and the Sahn-e Azade or Sahn-e Jadid (the new courtyard).