Jumna (Jamuna), the chief tributary of the Ganges, rises in the Himalayas in the State of Gurhwal, and flows in a south-easterly direction through the North-West Provinces, and after a course of about 700 miles enters the Ganges at Allahabad. Agra and Delhi are the chief towns on its banks. Its waters are used for irrigation purposes by means of the eastern and western Jumna canals. Its banks are high and its stream clear, but it is of little use for navigation in the greater part of its course during the hot season. It is nearly 11,000 feet above the sea-level at its source, but descends into the plains at an altitude of about 1,200 feet.