Located on the northeast of the Red Fort, Salimgarh was built by Islam Shah Sur (1545 – 1554 AD), also known as Salim Shar, son and successor of Sher Shah Sur (1540 – 1545 AD). It remained unfinished during Salim Shah's death in 1552. Roughly semi-circular on plan with a circuit of the walls about a km it originally stood on an island close to the west bank of Yamuna River.

A portion of Salimgarh fort, which the Archaeological Survey of India initially took over from the Indian army, has been developed in 1995 as a memorial to the Indian freedom fighters. The two barracks which were used to imprison Shah Nawaz Khan, Prem Kumar Sahgal, Gurbaksh Singh Dhillon and hundreds of other soldiers of the Indian National Army and other barracks are being maintained as a memorial. This memorial was originally a guard room constructed by the British army in 1916 AD. During the historical INA trial in Red Fort many of the prisoners were detained here.

The Archaeological Survey of India tool over these barracks from the Indian army in 1992 for conservation and preservation on the occasion of the 50th anniversary of Quit India movement and was dedicated to the INA heroes. INA uniform worned by Col. Prem Kumar, riding boots and coat buttons of Col. Gurbaksh Singh Dhillon, photographs of Netaji Subhash Chandra Bose and others are on display. In one of the galleries, excavated material and photographs of the excavation carried out by the Archaeological Survey of India inside the fort in 1995 are also on display.