The Triveni Sangam in Allahabad is a confluence of 3 rivers, the Ganges, Yamuna, and Saraswati. Of these three, the river Saraswati is invisible and is said to flow underground and join the other two rivers from below. Here the muddy and pale-yellow waters of the Ganges merge with the blue waters of Yamuna. While the Ganges is only 4 feet deep, the Yamuna is 40 feet deep near the point of their nexus. The river Yamuna merges into the Ganges at this point and the Ganges continues on until it meets the sea at the Bay of Bengal. At the confluence of these two great Indian rivers, where the invisible Saraswati conjoins them, many tirtha yatris take boats to bathe from platforms erected in the Sangam. This, together with the migratory birds give a picturesque look to the river during the Kumbha Mela, in the month of January. It is believed that all the gods come in human form to take a dip at the sangam and expiate their sins.
All over India, the meeting rivers amplify the holiness of the tirtha. Two rivers are better than one three even more auspicious. The great site of the meeting rivers in north India is the sangam, the confluence, of the Ganga and Yamuna at Prayaga, where the city now called Allahabad stands.
The Ganga has long been seen as the white river, bearing the mica laden waters of her Himalayan course, and the Yamuna, the blue river.
This description of the confluence of the Ganga and Yamuna seems to be referred to in one of the latest sections of the Rig Veda, which says,“Those who bathe at the place where the two rivers, white and dark, flow together, rise upto heaven. More than a thousand years later, the classical Sanskrit poet, Kalidasa, describes the confluence of the white”waters of the Ganga with the blue waters of the Yamuna as if they were a string of pearls and sapphires combined, or a garland of white and blue lotuses intertwined.
According to the Puranas, there is also a third river, the Sarasvati,