Since the Moghuls were nomads of the steppe, the boundaries of their territories seldom stayed the same for long. Still, Moghulistan in the strictest sense was centered in the Ili region. It was bounded on the west by the province of Shash and the Karatau Mountains, while the southern area of Lake Balkhash marked the northern limit of Moghul influence. From there the border gradually sloped in a southeastern direction until it reached the eastern portion of the Tian Shan Mountains. The Tian Shan then served as the southern border of Moghulistan. Besides Moghulistan proper, the Moghuls also nominally controlled modern-day Beijiang (northern Xinjiang, including the Turpan Depression) and Nanjiang (southern Xinjiang, including the Tarim Basin). Besides Moghulistan, Nanjiang, and Beijiang, several other regions were also temporarily subjected to Moghul rule at one time or another, such as Tashkent, Ferghana and parts of Badakhshan. Moghulistan proper was primarily steppe country and was where the Moghuls usually resided. Because of the Moghuls' nomadic nature, the towns of Moghulistan fell into decline during their rule, if they managed to remain occupied at all.