Qasba Mosque nine-domed mosque, which derives its name from the village Qasba under gurnadi upazila in Barisal district, is located a few yards away from the Barisal-Faridpur highway. The tank in front of the mosque, now almost dried up, appears to have been dug at the same time as the mosque to serve as an ablution pond.
This is a typical multi-domed square structure built entirely of well-burnt red bricks, save for the four stone pillars that support the domes on the roof. The walls are very massive with a thickness of 2.13m while the circular corner towers rise only up to the roof level. The mosque has three archways, on each of the north, south, and east sides. Of the three arches, the central one is the largest. It is to be noted here that in the north and south walls only the central archway is now open, while the flanking ones have been closed by brick filling. The three semi-circular mihrab niches inside the qibla wall are kept symmetrically large and small corresponding to the three entrances in the east wall.
The interior of the mosque is divided into nine equal square bays by four stone pillars. The domes, nine in total, rest on arches springing from the stone pillars. The four triangular corner spaces, formed by the intersection of arches just below the base of the dome in each bay, are filled with traditional Bengali pendentives. The four corner towers have slightly moulded bases and plain tops. The only cornice band of the building is curved in the Bengali fashion.
The decorations of the mosque consist only of terracotta depicting diaper, lozenge, scrolls, interlocking patterns and rosettes. These decorations are now seen in the mihrab niches and the doorway arches.
After restoration and repair by the Directorate of Archaeology the mosque has become one of the best preserved monuments in Bengal. It is now being used for prayers five times a day. The building is not dated by any inscription. Tradition has it that it was built early in the 16th century by one Sabhi Khan, whose identity is still unknown. But in plan, in measurement, in the arrangement of the interior apartments and the domes on the roof, in the setting of the door openings and the design of the corner towers, the Qasba Mosque appears to be a replica of nine-dome mosque of khan jahan at Bagerhat and the masjidkur mosque in Khulna. This strong affinity of the mosque with Khan Jahani buildings suggests of the fact that it might have been built in the middle of the 15th century, when the area appears to have been brought under Muslim control by Khan Jahan. [MA Bari]