Shaista Khan was the new subahdar of Dhaka in that time, and he did not complete the fort. In 1684, the daughter of Shaista Khan named Iran Dukht Pari Bibi died there. After her death, he started to think the fort as unlucky, and left the structure incomplete.[2] Among the three major parts of Lalbagh Fort, one is the tomb of Bibi Pari.

After Shaista Khan left Dhaka, it lost its popularity. The main cause was that the capital was moved from Dhaka to Murshidabad. After the end of the royal Mughal period, the fort became abandoned. In 1844, the area acquired its name as Lalbagh replacing Aurangabad, and the fort became Lalbagh Fort.[3]

The southern fortification wall has a huge bastion in the southwestern corner. On the north of the south fortification wall were the utility buildings, stable, administration block, and its western part accommodated a beautiful roof-garden with arrangements for fountains and a water reservoir. The residential part was located on the east of the west fortification wall, mainly to the southwest of the mosque.

The fortification wall on the south had five bastions at regular intervals two stories in height, and the western wall had two bastions; the biggest one is near the main southern gate. The bastions had a tunnel. The central area of the fort is occupied by three buildings – the Diwan-i-Aam and the hammam on its east, the Mosque on the west and the Tomb of Pari Bibi in between the two – in one line, but not at an equal distance. A water channel with fountains at regular intervals connects the three buildings from east to west and north to south.[1]

In 1874, Lord Northbrook, Governor General of India attended an evening function in the palace when he came to lay the foundation of a water works installed by Nawab Abdul Ghani. In 1888, Lord Dufferin also accepted the hospitality offered at Ahsan Manzil. In 1904 Lord Curzon, on a visit to East Bengal, stayed in this palace on 18 and 19 February to win public support for the proposed Partition of Bengal.

The fortification wall on the south had five bastions at regular intervals two stories in height, and the western wall had two bastions; the biggest one is near the main southern gate. The bastions had a tunnel. The central area of the fort is occupied by three buildings – the Diwan-i-Aam and the hammam on its east, the Mosque on the west and the Tomb of Pari Bibi in between the two – in one line, but not at an equal distance. A water channel with fountains at regular intervals connects the three buildings from east to west and north to south.[1]