AS darkness falls I join the crowds climbing the steep, winding streets towards the cathedral. It’s 5pm, winter-black already, and the bells are ringing. As they do, the front of the cathedral illuminates in harmony. Light runs across the face of the building like musical notation. Somewhere 300ft above us 60 bell-ringers are taking it in turns to pull and release and as they do so a huge electric lightshow plays out in rhythm.

It is a show that continues inside. This huge vaulted space strobes from sepulchral gloom to bright effulgence in time with the bells. The music of architecture melds with the architecture of music. Crowds shuffle through and look upwards towards the light. The Christian story rewritten in electricity.

Since 2009 this has been Durham’s story too. A city rewriting itself in light every other year. It comes with a title. Lumiere. The UK’s largest light festival, it is claimed, 29 artworks this year, of varying sizes, ranging from large to epic.

The cathedral’s lightshow is entitled Methods and is the work of Spanish artist Pablo Valbuena. Down below the cathedral music and light transform the riverbank into a blue-toned dreamscape, the work of Finnish artist Kari Kola. Above, on the side of Durham Castle, a huge moon-shaped face shines benignly down on the crowds below, courtesy of British artist Hannah Fox.

Over the next few nights more than 240,000 people will circle around the city – six times its normal population. People will “ooh” and “ahh” and spend money and remind everyone that culture is an economic force too.

“There are massive benefits for this city - £9m invested over the four days,” suggests Helen Marriage, the director of Artichoke Projects, the company behind Lumiere.

But it only works, she says, if the art is worth the investment. “They’re artworks. They’re not just the latest tricksy bits of projection mapping or CGI.

“We tread a line between spectacle and the artwork. It’s as different from Blackpool Illuminations as it can be.”

When the first Durham Lumiere was held in 2009, Marriage thought it would be a one-off. Some 75,000 attended that event and the numbers have grown ever since. “My contention is that none of that would be happening unless the work was remarkable,” she adds.

That said, the place is too. “You step off the train and you look down on that amazing panorama of a city, with the castle and the cathedral and the river winding through the landscape merging right into the city,” Marriage says. Remembering her first recce for Lumiere in 2009, she adds. “I stood looking and thought: ‘Oh yeah, I know how to do this.’ It was a complete reaction of love.”

Marriage has local links with the place. “My grandfather was born in Spennymoor just outside and he was the Methodist minister in Durham for a number of years, my mother was born here she married here.” Lumiere was in a way a homecoming for her.

I have history with this city too. In the early 1990s I lived here for a few years, working in Newcastle or commuting down at weekends from Scotland. Saturdays and Sundays would be spent eating cake in the Vennel Cafe in the city centre, showing family visitors the cathedral or just trying to get to grips with the place.

It has a Jekyll-and-Hyde aspect to it. The city centre is well-heeled but you don’t have to travel far to see the scuffmarks of an area that is still coming to terms with its post-industrial present.

People who live in villages only a few miles from Durham had never visited the city until Lumiere, research has found.

In its way Lumiere unites town and gown. Walk around the exhibits during the festival and you hear Durham accents while students dressed up in stiff-collared black ties walk past.

It’s a place where everyone, everything, rubs alongside each other. This bricolage is in the very walls. In the streets around the cathedral medieval stone squats next to 1960s brick and 1970s concrete.

Down at the bottom of the hill you can dip under a white lintel between shops in Silver Street and start to climb towards the cathedral. This was the original pilgrims’ route. Now it’s a cramped, enclosed, not very pretty, but pleasantly quiet corridor of brick and fencing. The storied past now invisible until you break free into Saddler Street.

And yet back up at Durham Cathedral the city’s place in the story of English Christianity is written in the stone. “The almost umbilical connection here with the origins of Christianity goes back to the 7th century,” the Dean of Durham, the Very Reverend Andrew Tremlett tells me. “The fact that so much of the heritage and the artefacts from those times have survived intact is quite incredible.”

In the cathedral’s Claustral Buildings some of those artefacts are on display in an exhibition, Open Treasure. Here you can see the remains of the wooden coffin of Saint Cuthbert, one of the fathers of English Christianity, on show in the Great Kitchen.

For the Dean it is the weight and stretch of that history that has most affected him since he arrived 18 months ago from Devon. He recites the names of Cuthbert, 7th-century monk and historian Bede, and 11th-century queen Margaret of Scotland.

All are part of the story of Durham, he says. Margaret in fact was in Durham for the laying of the cathedral’s foundation stone in 1090. “You feel,” the Dean suggests, “as if you are walking closely with them.”

Apparently, he tells me, evensong in the cathedral is never so busy as when Lumiere is on because everyone is hoping to sit in the cathedral waiting for the lights to switch on.

Certainly the afternoon before Lumiere kicks off that appears to be true. People are in their seats before the service even starts. Look around this building you can’t help but feel this structure is a physical manifestation of muscular Christianity. There’s none of York Minster’s frills and mimsy here. It is an epic, unadorned building. In the late afternoon sunlight glows pale gold in the high windows. Evens someone as militantly atheist as myself can’t fail to be impressed.

But then Durham is impressive. Next morning walking along the River Wear the only sounds to be heard are the idling hum of generators and birdsong and further upstream the dip and pull of oars as double sculls beat up and down the river. I am just a minute or two away from the city centre and yet the peace and quiet rings in my ears.

In short, there are worse places to spend your time. A few years ago I brought my daughters to Durham for the first time. As we walked across the Framwellgate Bridge they looked up at the castle and the cathedral and ahead at the shop-lined street as it wound its way up the hill and they both turned to me and said: “Why did you move from here?” I didn’t have an answer then. I’m not sure I have one this morning either.