Chechnya falls into three physical regions from south to north. In the south is the Greater Caucasus, the crest line of which forms the republic’s southern boundary. The highest peak is Mount Tebulosmta (14,741 feet [4,493 metres]), and the area’s chief river is the Argun, a tributary of the Sunzha. The second region is the foreland, consisting of the broad valleys of the Terek and Sunzha rivers, which cross the republic from the west to the east, where they unite.