 The river begins a little to the north of the Polar Circle at the confluence of the small rivers Orto-Muna and Ulakhan-Muna in the northeastern slopes of the Central Siberian Plateau at an elevation of .It flows roughly eastwards in a deep valley and, after leaving the mountainous region it meanders across the lowland among almost 2,500 lakes.The river broadens in the plain, reaching a width of when it meets the left bank of the lower course of the Lena.