As many as 400 million Hindu pilgrims are expected to visit Prayagraj, India, during this year’s 45-day Maha Kumbh Mela festival. Held every 12 years at one of four places in India, the Kumbh Mela is considered to be an especially auspicious time to bathe in the Triveni Sangam—the confluence of the Ganges, Yamuna, and mythical Saraswati rivers—for purification from sin.