The Idryn river ran from the mountains south of the city of Quon Tali through the north of the Dal Hon Plains and into the Bay of Nap at Cawn. Along its length it ran through the cities of Ipras, Idryb, and Li Heng.
The grey-green river was navigable by boat over much of its length, but the legendary Broke Earth Falls a few days west of Li Heng required portage to pass. These falls may have been the same as Idryn Falls which were a place of pilgrimage to Burn. There the earth was said to be cracked and shifted by the goddess' restlessness and a great spout of water that shot up from the falls' pool was believed to be Burn's very exhalation.