Haruniyeh is the oldest monument remaining from the ancient city of Tus, near Mashhad. The structure, which is close to the Tomb of Ferdowsi, lies in the middle of a lush garden. Nobody is really certain about the function of Haruniyeh Dome.
Some believe it served as a prison during the Harun al-Rashid era. They say the Abbasid Caliph locked up the seventh Shia Imam (Imam Musa al-Kadhim) and his devotees in this building. However, there is no historical documents to substantiate this claim. Some also believe it was a khanqah or the mausoleum of al-Ghazali, one of the most prominent and influential Muslim philosophers and theologians.
In fact, what historians acknowledge is a different story. They say there is no similarity between the pavilion and the structure of a prison during the Harun al-Rashid era. Archeological excavations confirm that the building dates back to early Sasanian era. This means the Haruniyeh Dome dates back to a period before Harun al-Rashid. They say it was a fire temple which was replaced by a mosque following the Muslim conquest of Persia.
Today, there is a museum next to the monument where visitors can get valuable insight into the history and architectural tradition of Khorasan. Iran’s National and Cultural Heritage Association has reconstructed the Haruniyeh Dome. The monument has now become a major attraction near Mashhad, drawing thousands of pilgrims and travelers each year.