The Indian city of Prayagraj is preparing for the Kumbh Mela. This massive Hindu festival has required the construction of a temporary city to accommodate the 450 million people expected to attend. Prayagraj,

Over the coming 45 days, an estimated 400 million Hindus are expected to come together for Maha Kumbh Mela. The festival is held every 12 years but the "Maha" or grand Kumbh Mela takes place only every 144 years, "marking the 12th Kumbh Mela and a special celestial alignment of the sun, moon and Jupiter", said The Guardian.