Dushanbe is situated at the confluence of two rivers, the Varzob (flowing from north to south) and the Kofarnihon. It is – above sea level; in the south and west, the elevation is closer to  – , while in the north and northeast it reaches  – . The north and east of the city is bounded by the Gissar range, which can reach up to  above sea level, and is bounded on the south by the Babatag, Aktau, Rangontau and Karatau mountains which reach a height from  – above sea level; Dushanbe, therefore, is an intermontane basin located in the Gissar Valley. It has a primarily hilly terrain. 80% of Dushanbe's buildings are located within the valley, which has a width of approximately –. Before the 1960s, most of Dushanbe was located on the left bank of the Varzob river, but increased construction led to the city expanding across it.