Mirzanagar Mosque, Jessore is the only surviving monument of the Nawabbari (Nawabbadi) complex of Mirzanagar, a small village on the right bank of the Kobadak under Keshabpur upazila of Jessore district. In James Rennel's map (1781) Mirzanagar appears as an important town of Jessore. The place appears to have grown into prominence under two Mughal Faujdars - Mirza Shafshikan (died in 1664) and Narullah Khan (who resided here in 1696) - who are known to have had their seat of administration here. The Nawabbari complex and the Killabari of Mirzanagar are attributed to these Faujdars.
The outer surface of the four walls of the ruinous mosque has been seriously damaged, the four octagonal corner towers have disappeared and the super structure crumbled down. Nevertheless enough still survives to reconstruct an idea of its original form and design. It is oblong in plan, the interior is divided into three equal square bays by two lateral arches, traces of which still survive. The three domes, which originally covered the mosque, directly rested on the lateral arches and the walls. And the phase of transition was achieved by means of the sultanate Bengali pendentives, for the over-sailing courses of bricks set corner-wise and edge-wise are still seen across the upper angles of the northern bay.
The mosque has three four-centred archways on the east and one on each of the north and south walls. The central opening in the east wall was larger than the flanking ones. The qibla wall accommodates three semi-octagonal mihrabs, of which the central mihrab is bigger and shows a rectangular projection towards the back, now badly damaged. The building was originally covered with polished plaster, still intact at different places of the existing four walls.
J Westland, who for the first time wrote on the Mirzanagar ruins, identified the building as the residence proper of the Nawab or the Faujdar. Following him AH Dani and others simply call it a residential building. But the existence of three mihrabs inside the building is a clear indication that it was a mosque and is still being used for the same purpose having been covered with a chau-chala roof of CI sheets. [MA Bari]