The Archaeological site museum at Purana Qila is located inside the fort and to the right of the main entrance. The excavations at Purana Qila were carried out by the Archaeological Survey of India in 1955 and again from 1969 to 1973. The exhibits in this museum are largely based on the excavated materials. These excavations have revealed evidence of earliest settlement at this site datable to around 1000 BC, represented by Painted Grey ware and with a continuous cultural sequence from Mauryan to Mughal through Sunga, Kushana, Gupta, Rajput and Sultanate periods.
In the site museum, various objects and pottery recovered during the excavations from the stratas of different periods has been put on display. The museum also has exhibits of antiquities that have been recovered from various parts of Delhi.