Four glacial valleys – the Chaudefour valley to the Northeast, the Fontaine Salée valley to the South, the Dordogne valley to the North and the Biche valley to the West – start from the slopes of the Sancy massif (photo). Several streams also take their source in the valleys, such as the Dore at 5,511 feet (1,680 metres) of altitude and the Dogne at 5,380 feet (1,640 metres) which meet at 4,494 feet (1,370 metres) to form the Dordogne river.