Khwaja Alimullah bought some properties including this building from the French traders in 1835, which was originally owned by Zaminder Seikh Enayetullah. Nawab Abdul Ghani named Ahsan Manzil after his son Nawab Ahsanullah. It is a magnificent pink-coloured building with an imposing staircase leading to the upper floor, and it is topped by a lofty dome. In each of the 23 grand rooms there is a photograph of the room dating back from around 1902, and these photos allowed the accurate restoration of the furnishings and draperies. Ancestors of the Khwaja Alimullah came from Kashmir in search of fortune. The Nawabs played a significant role during their regime around 100 year, uplifting the life style of the people as they were the pioneer to provide the following services: Electricity, Health care system, Sanitation, School and colleges, Parks, River-reforms, banking, etc. It has been turned to a museum which will give a good insight into the life of the ruling classes of Bengal during the British Raj.