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.