“ Nearly the whole district is a maze of mountains intersected by deep ravines, the only level land of any considerable extent being found in the valley of the Yōnzalīn, While the country is covered with dense forest, of which 128 sq. m. are reserved. The district is drained by three principal rivers, the Salween, Yōnzalīn and Bilīn, fed by mountain torrents. The Yōnzalīn, which rises in the extreme N., is navigable with some difficulty in the dry season as far as Papun ”