The name promises sixty domes; there are eighty-one, carried on sixty stone pillars that turn the prayer hall into a forest of arches. It is the largest mosque of medieval Bengal, and you see it coming across the rice fields — low and broad, like a brick warehouse. A warrior-saint raised it in the fifteenth century as the centre of a whole city built in the marsh, now reduced to a scatter of mosques among the villages. Beside it lies a vast dug tank, the only fresh water in a tidal delta.