Purana Qila, originally called Dina-panah, was founded by the second Mughal Emperor, Humayun in 1533 at the site of ancient city of Indraprastha founded by the Pandavas.

It stands on an ancient mound, and excavations near its eastern wall have revealed that the site has been continuously occupied since 1000 BC. It is also believed to be the place where Indraprastha, the Pandava capital mentioned in the epic Mahabharata, once stood. Purana Qila and its environs flourished as the sixth city of Delhi.

The Citadel & its History
Purana Qila, yet another monument on the banks of Yamuna, is associated with Mughal emperor Humayun. It is where Humayun's capital Din Panah was located. Later it was renovated and named Shergarh by first Afghan emperor of India, Sher Shah Suri.

Qila-i-Kuhna Mosque
The single-domed Qila-i-Kuna Mosque, built by Sher Shah in 1541 is an excellent example of a pre-Mughal design. The prayer hall inside has five elegant arched niches or mihrabs set in its western wall.

Marble in shades of red, white and slate is used for the calligraphic inscriptions and marks a transition from Lodhi to Mughal architecture. A second storey provided space for female courtiers to pray, while the arched doorway on the left wall, framed by ornate jharokas, was reserved for members of the royal family.

Sher Mandal
The Sher Mandal stands to the south of the mosque. This double-storeyed octagonal tower of red sandstone was built by Sher Shah and was used as a library by Humayun after he recaptured the fort.

The tower is topped by an octagonal chhatri supported by eight pillars and decorated with white marble. Inside there are remnants of the decorative plaster-work and traces of stone-shelving where, presumably, the emperor's books were placed. This was also the tragic spot where, on 24 January, 1556 Humayun slipped off the stairs, missed his footing and stumbled to his death.