Turkmenistan's average elevation is 100 to 220 meters above sea level, with its highest point being Mount Aýrybaba (3,139 m) in the Köýtendag Range of the Pamir-Alay chain in the south-east, and its lowest point being the Akjagaýa Depression in Sarygamysh Lake, close to 100 meters below sea level (the actual water level in Sarygamysh Lake fluctuates widely from -110 m at its shallowest to -60 m).. The Mount Arlan rises sharply above sea level in the Great Balkhan Range in western Turkmenistan (Balkan Province). Nearly 80% of the republic lies within the Turan Depression, which slopes from south to north and from east to west.