PRAYAGRAJ, India — Beside India's holy rivers, a makeshift city is being built for a Hindu religious festival expected to be so vast it will be seen from space, the largest gathering in history.
Line after line of pontoon bridges span the rivers at Prayagraj, as Indian authorities prepare for 400 million pilgrims — more than the combined population of the United States and Canada — during the six-week-long Kumbh Mela.
