Delhi had at its centre the fortress of Purana Qila, which reputedly stands on the site of Indraprastha, the city of the Pandavas in the Mahabharata. Of the buildings that survive today, the Qila-i-Kuhna Masjid, a successful fusion of the Islamic and Hindu styles, was constructed by Sher Shah in 1541. The Sher Mandal is an octagonal observatory and library. The north gate, Talaqi-Darwaza, has been partially rebuilt and gives an impression of how formidable the fortifications would have been in their heyday. The chattri surmounting the west (entrance) gate commands a fine view of
New Delhi. Purana Qila is undergoing restoration. There is a small museum just inside the south gate.