Yamuna or Jumna (ancient Jomanes), river, northern India, principal tributary of the Ganges, rising in the western Himalayas, near Kāmet peak. After pursuing a southerly course of about 153 km (about 95 mi), the Yamuna enters the plains north of Sahāranpur and follows a winding route past Delhi and Āgra to Allahābād, where it joins the Ganges, after a course of 1,400 km (870 mi). The confluence of the Yamuna and Ganges is a place of pilgrimage for Hindus. The river is navigable by barge, and it is used for irrigation purposes.