Elevations are generally moderate, little above 2,000 metres (6,600 ft) for the highest summits. There is a wide range of elevations though, with floors ranging between 200 and 500 metres (660 and 1,640 ft) above sea level. Towards the Lao border, the divide to the Mekong basin becomes higher with peaks occasionally rising above 1,500 metres (4,900 ft) and streams flowing in narrow steep valleys.[1]