Kosambi was a fortified town with an irregular oblong plan. Excavations of the ruins revealed the existence of gates on three sides-east, west and north. The location of the southern gate can not be precisely determined due to water erosion. Besides the bastions, gates and sub-gates, the city was encircled on three sides by a moat, which, though filled up at places, it still discernible on the northern side. At some points, however, there is evidence of more than one moat. The city extended to an area of approximately 6.5 km. The city shows a large extent of brickworks indicating the density of structures in the city.