Thousands wait for the god Vishnu to appear

The confluence of the rivers Yamuna and Ganges just outside Allahabad's medieval city walls is usually a quiet waste of white sand where small boys play scratch games of cricket. But this week, these sand flats became point zero of an enormous city that sprang up practically overnight.

The confluence of the rivers Yamuna and Ganges just outside Allahabad's medieval city walls is usually a quiet waste of white sand where small boys play scratch games of cricket. But this week, these sand flats became point zero of an enormous city that sprang up practically overnight.

The Kumbh Mela, which may, if the authorities' predictions are fulfilled, become the biggest gathering of human beings for a single purpose in history, opened yesterday. Already, tens of thousands of Hindu pilgrims and ascetics are camped on the banks and most of them have immersed themselves in the cold, swirling, slug-brown waters.

According to Hindus, this is one of four places along the Ganges where the god Vishnu spilt drops of heavenly nectar. At particular astrological moments when Jupiter is in Aries, the faithful believe that the waters are transformed into nectar, and that to bathe in them is to attain Mokha, liberation from the cycle of birth and death. That core item of belief is the reason up to 70 million Hindus will make the journey to Allahabad over the next 40 days. The alignment of the planets will not be as auspicious again for 144 years.

The police have laid 75km (46 miles) of steel plate roadway, thrown 15 pontoon bridges across the rivers and laid tons of sandbags to stop the river banks eroding. Around this infrastructure, the pilgrims make a city that may be modern in scale and in some of its amenities but whose mood and texture are as old as their religion.

The city is materialising before one's eyes. Squatting on the ground, artisans stitch together bamboo lattice structures that will form the entrance ways to the areas occupied by different sects. By the side of the road a young renunciate is having his head shaved. A dromedary slouches by, laden with bamboo poles. Between the forests of tents are mountainous stacks of roughly cut timber, awaiting the night's bonfires. A woman in a blue cotton sari glides by, eight bricks balanced on her head. Down by the sangam, the confluence point, the holiest spot in the site, a group of women huddle, chanting, around a small child, while a man with a razor painstakingly shaves her head, collecting the hair in a clay dish. Out on the river, boatmen punt simple craft, groaning with pilgrims, to the vortex of the confluence, where they climb over the side and immerse themselves in a channel that is nowhere deep.

Immersion and consequent liberation is the raison d'etre of the festival, but, like all great pilgrimages, it attracts a host of other activities. Most of India's half million sadhus, Hindu ascetics, will assemble here over the next month and a half, many stark naked, their uncut hair matted, their bodies smeared with ash, some dashing perilously on frisky Arab horses. Others brandish cutlasses and tridents to menace those who might prevent them being first into the water in a way that is not obviously pious. Between the ritual bathing, the sadhus debate issues of moment to their respective sects, sign up new recruits, expel those who have done wrong - and openly smoke large chillums of hashish or opium.

All the mind-boggling guises of Hinduism are on display: the famous ascetic who has stood with one arm held rigidly in the air for decades; the ancient sages with waist-long hair, bound up with saffron cloths and piled lazily atop their heads. Thousands of grizzled, elderly men gather here, each wilder looking than the one before. Hindus, strait-laced and conformist in adolescence, reserve their interlude of unbridled individualism for extreme old age - for, according to their religion, once the duties of life have been performed, a man can prepare himself for the hereafter as he sees fit.

Down by the sangam, a big orange sun set on a scene that a stoned Canaletto might have painted, as dozens of brimful little ferries hunted back and forth. As the daylight waned, the medieval city disappeared and a quite different place sprang into life. It was like a huge fairground or a sort of ad-lib religious Las Vegas. All over the immense site, neon archways lit up, some of great kinetic sophistication, spraying colours and patterns, luring the devout and the curious into the presence of the sages holding court behind their portals.

Ten thousand loud speakers likewise sprang into discordant, cacophonous life - chants, song-bird warbles, hymns, wheezing harmoniums, sermons. And then came the lighting of the bonfires, and soon the air was dense and pungent with wood smoke.

Before dawn this morning, marking the auspicious lunar eclipse, up to a million of the faithful are expected to brave the near-freezing water of the river. The city of the Kumbh Mela, bright and brief as a firefly, is alight.