This TED Talk features architect and urbanist Rahul Marotra, recorded live at TED 2019.

On this planet today, there are about 50 cities that are larger than 5 million people.

I'm going to share with you the story of one such city, a city of seven million

people, but a city that's a temporary mega city, an ephemeral megacity. This is a city that is built

for a Hindu religious festival called the Kumb Mela, which occurs every 12 years in smaller editions every four years,

and takes place at the confluence of the Ganges and the Yamuna rivers in India.

And for this festival, about a hundred million people congregate.

The reason so many people congregate here

is the Hindus believe that during the festival,

the cycle every 12 years,

if you bathe at the confluence of these two great rivers,

you are freed from rebirth.

It's a really compelling idea.

You're liberated from life as we know it.

And this is what attracts these millions. And an entire megacity is built to house them.

Seven million people live there for the 55 days and the other 100 million visit.

After the monsoon, as the waters of these rivers begin to recede,

and the sandbanks expose themselves,

it becomes the terrain for the city.

And by the 15th of January, starting, 15th of October to 15th of January,

in these weeks, an entire city emerges, a city that houses

seven million people. What is fascinating is this city actually has all the characteristics

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