The principal rivers of Arakan Division included the Naaf estuary, in the north, which forms the boundary between the division and Chittagong; (2) the Mayu River, an arm of the sea, running a course almost parallel with the coast for about 50 m.; (3) the Kaladan River, rising near the Blue mountain, in the extreme north-east, and falling into the Bay of Bengal a few miles south of the Mayu River, navigable by vessels of from 300 to 400 tons burden for a distance of 40 m. inland; and (4) the Lemro River, a considerable stream falling into the bay a few miles south of the Kaladan. Farther to the south, owing to the nearness of the range which bounds Arakan on the east, the rivers are of but little importance. These are the Talak and the Aeng, navigable by boats; and the Sandoway, the Taungup and the Gwa streams, the latter of which alone has any importance, owing to its mouth forming a good port of call or haven for vessels of from 9 to 10 ft. draught. There are several passes over the Arakan Mountains, the easiest being that called the Aeng route, leading from the village of that name into Upper Burma. The staple crop of the division was rice, along with cotton, tobacco, sugar, hemp and indigo. The forests produce abundance of excellent oak and teak timber.