The average elevation of the central plateau is , with lower elevations at the borders. The highest peak, Mount Heha at , lies to the southeast of the largest city and economic capital, Bujumbura. The source of the Nile River is in Bururi province, and is linked from Lake Victoria to its headwaters via the Ruvyironza River. Lake Victoria is also an important water source, which serves as a fork to the Kagera River. Another major lake is Lake Tanganyika, located in much of Burundi's southwestern corner.