Yamuna (yäˈmənə) [key] or Jumna jŭmˈnə, river, c.850 mi (1,370 km) long, rising in the Himalayas, N India, and flowing generally SE, through the Shiwalik Range, past Delhi, to the Ganges River at Allahabad, Uttar Pradesh state; the Chambal and Betwa rivers are its main tributaries. The Yamuna's confluence with the Ganges is sacred to Hindus; Allahabad is a major pilgrimage center. Along the Yamuna's banks are many historic monuments, including the Taj Mahal at Agra. Formerly an important trade artery, the Yamuna is now the source of irrigation for Uttar Pradesh and Punjab states, and it also suffers from heavy pollution, most especially in the Delhi area. As a result, the river is, except during the monsoon season, severely polluted and greatly reduced in flow below Delhi. The East Yamuna, West Yamuna, and Agra are the major canals on the river.