Mbh 3.85.2e

Then, O king, should one proceed to Prayaga, whose praises have been sung by Rishis and where dwell the gods with Brahma at their head, the Directions with their presiding deities, the Lokapalas, the Siddhas, the Pitris adored by the worlds, the great Rishis-Sanatkumara and others, stainless Brahmarshis--Angiras and others,--the Nagas, the Suparnas, the Siddhas, the Snakes, the Rivers, the Seas, the Gandharvas, the Apsaras, and the Lord Hari with Prajapati. There in that tirtha are three fiery caverns between which the Ganga, that foremost of tirthas, rolleth rapidly. There in that region also the world-purifying daughter of the sun, Yamuna, celebrated over the three worlds, uniteth with the Ganga. The country between the Ganga and the Yamuna is regarded as the mons veneris of the world, and Prayaga as the foremost point of that region. The tirthas Prayaga, Pratisthana, Kamvala, Aswatara and Bhogavati are the sacrificial platforms of the Creator. There in those places, O foremost of warriors, the Vedas and the Sacrifices, in embodied forms, and the Rishis endued with wealth of asceticism, adore Brahma, and there the gods and rulers of territories also celebrate their sacrifices. The learned, however, say that of all these tirthas, O exalted one, Prayaga is the most sacred, in fact, the foremost of all tirthas in the three worlds. By going to that tirtha, by singing its praises, or by taking a little earth from it, one is cleansed from every sin. He that bathes in that confluence celebrated over the world, acquires all the merits of the Rajasuya and the horse-sacrifices. This sacrificial place is worshipped by the gods themselves. If a man giveth there ever so little, it increaseth, O Bharata, a thousandfold. O child, let not the texts of the Veda, nor the opinions of men dissuade thy mind from the desire of dying at Prayaga. O son of the Kuru race, the wise say that six hundred million and ten thousand tirthas exist at Prayaga.