Photograph of the Diwan-i-Am in Agra fort, from the Archaeological Survey of India Collections taken by Joseph David Beglar in the 1870s. The Agra fort complex stands on the banks of the Yamuna and was built by the Emperor Akbar between 1565 and 1573. Built principally as a military establishment on the site of an earlier walled complex, the fort is considered the predecessor of the Delhi Red Fort. The massive walls of the fort, built of red sandstone, are 20 feet high and 2.5km long with curved bastions at intervals. Emperor Shah Jahan (r.1628-58) was responsible for the Mughal buildings within the fort and the Diwam-i-Am was the Hall of Public Audience. It consists of three aisles of nine bays open on three sides with peacock arches carried on red sandstone columns. At the back is the throne-alcove of inlaid marble for the Emperor's throne.