Are there not thousands of cities full of treasures at every step? But Shiva, I swear to you, I have nowhere laid eyes on a city such as Kashi. – Kashi Khanda

Between the eleventh and the seventeenth centuries, virtually all of Banaras was demolished by successive invaders. In the late twelfth century Qutb-ud-din Aibak, a former slave who became a sultan, almost levelled the city to the ground, destroying more than a thousand temples in the process.The sixth Mughal emperor Aurangzeb razed many more, including, in 1669, the Kashi Vishwanath temple, Hinduism’s holiest site.

This litany of destruction confirms the sense that the city itself is not bricks and mortar, but something more resilient.

No matter what history throws at it, it seems to survive. And yet part of me wonders whether, at long last, the city might have met its match.The much-feted modernisation of India is affecting changes in the social landscape here that might prove as destructive to Varanasi’s makeup as any army.

India’s growing economy and the explosion in connectivity to the Internet are changing the aspirations of its young people in radical ways. Caste and faith – the ties that have held Indian society together for so long – are fraying, as the Western model, based on individualism, enters the picture. This is all going to affect Varanasi in ways no one can predict.

In the newest districts of the city – little more than clusters of new concrete buildings, really – the old structures are noticeably absent.

It is as if a painter, schooled for several thousand years in a certain mode of creation, has suddenly discarded all that has gone before. These districts have no wells, wrestling arenas, shrines or headmen. They are simply groupings of featureless architecture in which human beings find refuge and try to make a life for themselves.

In the days when my explorations took me to the fringes of the city, I found myself grateful for return to the familiarity and lyricism of the river bank. From this I concluded certain things: that we humans are comforted by order and ritual, are threatened by change and are nourished by modes of living that appear to lead us to a kind of fruition. Whether we can live without these things represents the great uncertain experiment of the future, but not one entirely without hope.

My year in Varanasi was an opportunity to witness the continuing evolution of an ancient city in real time. Just as in Hindu scriptures Vishnu takes the form of a fish, a turtle, then a boar, so India’s holiest place is reincarnating herself moment by moment. Yet what is most striking about this apparent battle here is that the city’s personality seems almost entirely allied with the older mode of being.

This is a conservative city, a city that draws its identity from the past, unlike, say, Bombay, whose lure for many Indians is its newness – a place, like America, where one can reinvent oneself.

Varanasi is a place where reinvention is something of a dirty word. If people flock to Bombay to embrace modernity and find material wealth, they flock here to seek salvation and to leave the material behind.

I had an encounter, on one of my pre-dawn walks around the city, a conversation that seemed to encapsulate so many of my feelings about this shifting kaleidoscope I was trying to freeze-frame.

At Chauki Ghat, I fell into conversation with an old man drawing sketches of the river: free-form, quite avant-garde approximations of the Ganga, using biro on old torn scraps of notebook.

The pictures had a power and authority about them that far exceeded the artist’s technical skill. He wore the black robes of a mendicant, and spoke precise, eloquent English in a soft voice.We sat taking amiably as the first rays of sun broke through the clouds, talking of art and philosophy and the city we were both attempting to sketch. Before us, the surface of the river was utterly still, except where bisected by the prow of a solitary fishing craft.

‘You will never know this city,’ he said, while his bony fingers scratched the crescent sweep of the river. ‘You will never know it because it only exists in here’ – he tapped his skull.

‘It is merely an idea. So there is my city, your city, his city’ – he pointed to a passing boatman – ‘and all the millions of cities that coexist.That is the true meaning of Varanasi, it is a city of the heart actually, that place we’re all trying to get to.’

I nodded back at the old man. This was the kind of conversation Varanasi seemed to engender like no other place on earth. And he made a lot of sense. The city was an idea, a totemic symbol as much as it was bricks and stone.

‘I’m echoing Kabir really,’ he continued.‘He was this city’s greatest son: a poet, iconoclast, but ultimately a unifying figure. Kabir would go to the yogis and tell them: “If levitation is so impressive, how come the kites and crows can already do it?”’ He chuckled. ‘He would go to priests and say: “If shaving your head brings salvation, why aren’t all the sheep saved!”’

I found myself laughing too.‘Sounds like he knew how to stir things up.’

‘Oh yes,’ the old man dabbed at his eyes.‘But he did it for a reason. He was pointing to a place beyond division, beyond categories of any kind. In this city so many things meet. Everything pools together: the present and the past, all the ways humans have tried to comprehend God, and so many of the great cultural traditions of north India, too. But the message of this place, and the reason for the city’s long association with death, is that everything that is static dissolves in the end. It dissolves into the place Kabir was pointing to: the Great Mystery itself.’

The old man turned back to his drawing, tore it from the pad and presented it to me.

‘Like the mighty Ganga herself,’ he said, pointing to the silently flowing water in front of us.‘Everything just keeps on flowing.’

Excerpted with permission from Kaleidoscope City: A Year in Varanasi, Piers Moore Ede, Bloomsbury.