The Khan Mohammad Mridha Mosque on Lalbagh road is situated less than half a kilometre west of the Lalbagh Fort. Two Persian inscriptions, one over the central archway and the other over the central Mihrab, speak of its construction during 1704–05 AD by one Khan Muhammad Mridha.
The large platform is 38.10 m from north to south and 28.96 m from east to west. Its height is about 5.18 m from the ground level. Underneath the platform are vaulted rooms on all sides except the eastern side. In the eastern side, there is a stairway which ends with a gateway aligning the central doorway of the mosque proper. It is through this gateway that one can reach the top of the platform.
The prayer hall is a rectangular structure measuring 48′ x 24′ and is capped by three domes, the central being the larger one. The smaller sizes of the side domes are achieved by using intermediary pendentives. The corners minarets are short and slender, rising just above the parapet and are capped by ribbed copulas. The annex to the north of the mosque serves as a madrasa or religious school and has a hujra or arcaded hall that is used for travelers and visitors. The facade of the mosque is decorated with paneling and ornamental merlons along the parapet. The entrances to the prayer hall are framed by multi-cusped arches and engaged columns on either side.