A six-week Maha Kumbh Mela or Great Pitcher Festival begins in India on Monday, a Hindu sacred event that will be the world’s largest gathering of humanity as it showcases religion, spirituality, tourism and crowd management.

More than 400 million people are expected in the northern city of Prayagraj in Uttar Pradesh state over the course of six weeks to take a holy dip at the confluence of three sacred rivers - the Ganga, the Yamuna, and the mythical, invisible Saraswati.

Devout Hindus believe taking a dip in the sacred waters absolves people of sins, and during the Kumbh Mela, it also brings salvation from the cycle of life and death.

The festival has its roots in a Hindu tradition that says the god Vishnu wrested a golden pitcher containing the nectar of immortality from demons.

In a 12-day celestial fight for possession, four drops fell to earth, in the cities of Prayagraj, Haridwar, Ujjain and Nashik, which host the festival every three years by rotation. The Kumbh held once every 12 years in this cycle has the prefix ‘maha’ (great) as it is considered more auspicious due to its timing and attracts the largest gathering.

The Kumbhs are a big test for authorities to showcase India’s ability to organise and manage the movement of millions of people and retain the ancient festival’s sanctity.

A sprawling 4,000 hectares of open land along the banks of the rivers has been converted into a temporary city to house the visitors in 150,000 tents and comes equipped with 3,000 kitchens, 145,000 restrooms and 99 parking lots.

Authorities are also installing up to 450,000 new electricity connections, with the Kumbh expected to drain more power than what 100,000 urban apartments in the region consume in a month.

Indian Railways has introduced 98 special trains that will make 3,300 trips during the festival to transport visitors besides regular trains that connect Prayagraj.

Prashant Kumar, the police chief of Uttar Pradesh, said around 40,000 police personnel and cybercrime experts have created a web of surveillance powered by artificial intelligence (AI) to protect and help navigate the sea of humanity at the site.”Security and safety of pilgrims is our priority,” said Kumar.

Emergency response capabilities include 125 road ambulances, seven river ambulances and air ambulances for swift medical assistance.

“I am fortunate to host one of the most auspicious Hindu festivals in my state,” state Chief Minister Yogi Adityanath told the Aaj Tak TV channel.

Adityanath is also a powerful Hindu monk and a popular hardline Hindu politician in Prime Minister Narendra Modi’s Bharatiya Janata Party (BJP).

A successful Maha Kumbh is expected to burnish the BJP’s record of reclaiming and glorifying India’s religious and cultural symbols for its Hindu base, promised by Modi and Adityanath since their Hindu nationalist party swept to power nationally in 2014.

The state government has allocated 64 billion rupees ($765 million) for this year’s event, officials said. It has also promoted the Kumbh Mela at several international tourism expositions and invited foreign representatives.

In 2021, Modi’s government had refused to call off the Kumbh festival despite a sharp rise in COVID-19 cases and allowed thousands of ash-smeared ascetics and devout Hindus to take a dip in the Ganga, possibly fearing a backlash from religious leaders in the Hindu-majority country.