In the south Semiryechensk embraces the intricate systems of the Ala-tau and the Tian-shan.
South of the lake two ranges of the Tian-shan, separated by the valley of the Naryn, stretch in the same direction, lifting up their icy peaks to 16,000 and 18,000 ft.; while westwards from the lake the precipitous slopes of the Alexander chain, 9000 to io,000 ft.
Southwards from the last-named, however, at the foot of the mountains and at the entrance to the valleys, there are rich areas of fertile land, which are being rapidly colonized by Russian immigrants, who have also penetrated into the Tian-shan, to the east of Lake Issyk-kul.
The Chu rises in the Tian-shan Mountains and flows north-westwards through Akmolinsk; and the Naryn flows south-westwards along a longitudinal valley of the Tian-shan, and enters Ferghana to join the Syr-darya.
High plateaus like that of Pamir (the " Roof of the World ") and Armenia, and lofty mountain chains like the snow-clad Caucasus, the Alai, the Tian-shan, the Sayan Mountains, exist only on the outskirts of the empire.