The average elevation of the province is 580 metres (1,900 ft). The north of the province is part of the so-called Golden Triangle, where the borders of Thailand, Laos and Burma converge. The Mekong River forms the boundary with Laos, the Mae Sai and Ruak River with Burma. Through the town of Chiang Rai itself, flows the "Mae Kok" Kok River and south of it the Lao River, a tributary of the Kok