In Hindu tradition, Triveni Sangam is the confluence of three rivers that is also a sacred place, with a bath here said to flush away all of one's sins and free one from the cycle of rebirth.
The Triveni Sangam, the intersection of the Yamuna River and the Ganges River
Pilgrims at the Triveni Sangam, the confluence of the Ganges, Yamuna and a sacred third river, the Sarasvati, at Prayag.
In geography, a confluence occurs where two or more watercourses join to form a single channel. A confluence can occur in several configurations: at the point where a tributary joins a larger river ; or where two streams meet to become the source of a river of a new name ; or where two separated channels of a river rejoin at the downstream end.
Confluence of the Bhagirathi and Alaknanda Rivers to produce the Ganges at Devprayag, India
The same confluence viewed from upstream at a different time; note the swirl of sediment from the Alaknanda.
The fountain at Point State Park in Pittsburgh, at the apex of the confluence of the Allegheny (top) and the Monongahela
The White Nile and Blue Nile merge at Khartoum; April 2013 satellite view