STEPHEN LEWIS tests out the snow at Yorkshire's new activity centre, where it snows every night.

"LEAN forward!" instructs Alex Momtchilov as he slides backwards down the slope ahead of me. "You have to lean forward. If you put your weight back, you lose control of the front of your skis."

I hear what you're saying, Alex, I think to myself grimly. But lean forward while I'm going down the slope? You've got to be kidding!

I quickly find out he's not. Instinctively, as I begin to slide down a slope that suddenly seems far bigger than it did from the bottom, my body leans backwards. The weight lifts from the front of my skis - and I start to go faster. There's a flash of panic, I hear Alex saying something about "Where's the V? Where's the V?", there is a spray of snow, and then I'm sitting in an ungainly heap half way down the slope.

It snows every night at Castleford. Real snow, produced by 16 snow guns firing cooled water into air chilled to minus two degrees. I can see them now, high up above me in the hangar ceiling of the real snow slopes at the indoor Xscape extreme sports centre. And I can testify to the fact it is real snow. It's cold. And wet. And I'm sitting in it.

Alex helps me to my feet, and my first skiing lesson continues.

There are two ski slopes at Xscape. The nursery slope, which is where I am, and the main piste, which looks for all the world like an Alpine slope, rearing up at the opposite side of the great hangar.

There are real ski-lifts climbing up the side, and expert-looking skiers zig-zagging down from the top at high speed, sending sprays of clean, fresh snow up at each turn.

Skis and I don't agree with each other - not at first, at least. From the moment I put them on, fitting the front of my snow boots into a special flange and then snapping my heel down to lock the ski as Alex teaches me, my feet no longer feel like my own. They are huge, ponderous things that threaten to get tangled up and knock down anyone who comes near.

Alex proves to be an expert instructor, however, and before long he has me side-stepping efficiently up the side of the nursery slope, digging in the rim of my skis on the up-hill side for grip.

I learn to walk - you have to slide, Alex says, not pick your feet up - and then I'm skating over to the drag rope at the side of the nursery slope which will whisk me up to the top. It's a moving rope: close your hands round it, and it effortlessly tugs you all the way up. Providing, that is, your skis don't try to take you in another direction.

Safely at the top, I practice the V-shape. Keeping the tip of the skis fairly close together, you splay out the rear, to create an inverted V. It makes the skis act as a snowplough, Alex explains, so that you can control your speed. The wider the V, the slower you go. Straighten your skis, and you go faster. Lean back, as I was soon to find, and you go faster still.

The slope had seemed small and tame from the bottom. From up here, it seems steep. And my skis seem worryingly eager to take off. Keep the V, Alex tells me, going backwards just ahead of me. Keep the V. Lean forward.

I manage it for at least ten feet. Then my body insists on leaning back. My skis straighten, the bottom of the slope rushes at me, and I find myself in a heap, ploughing up a furrow of snow.

Entirely unhurt, however, apart from my dignity. And by the end of my one hour lesson, I have skied down the slope twice, and have even learned to do 'snowplough turns'. "The way you're going," Alex tells me, "you'll be on the main slope from the next lesson." I look at it and gulp. But inwardly I vow, like the new California governor, that I'll be back.

Afterwards, I'm given a guided tour around the new Xscape leisure centre, which is handily located for York off Junction 32 of the M62. I quickly realise that it is far more than just the North's first indoor real snow slope, great though that is. Xscape bills itself as the ultimate sports entertainment and shopping destination - and it pretty much lives up to that billing.

There's a 14-screen cinema; a 20-lane bowling alley; restaurants, bars and shops, more of which are to open soon; and, still under construction, an ice cliff nearly 50 feet high made with real ice, where mountaineers will be able to practice their ice-climbing skills.

And, perhaps best of all, there's the ClimbZone, a towering red 'rockface' that greets you as you walk through Xscape's main entrance. Hard-hatted climbers in harness and rope are sashaying up its sheer face - among them children under the guidance of instructors. And way up at the top, slung under the roof at the lip of the rockface, is the Sky Ride - and aerial obstacle course. This moving, swaying, dangling walkway is made up of logs, nets and wooden frames slung from the ceiling. It looks fantastic - and I can't resist.

Lead instructor Alan Taylor, who has a reassuring Scottish accent, clips me into a safety harness that hangs from a moving trackway. To get to the Sky Ride you have to make the Leap of Faith, he says - launching yourself into empty space from the top of the cliff and allowing your harness to carry you across a gap of ten feet or so to the first piece of dangling wood.

"Don't worry. It is absolutely safe," he assures me. "And it will give you a real adrenaline high."

He's right. It does. First terrifying leap over, you find yourself swinging from log to log, grappling at the underside of wooden frames, scrambling across army-style assault nets - with all the time the floor a dizzying 50 feet below.

It's simultaneously terrifying and exhilarating and, because of the safety harness, perfectly safe. Just as Alan said.

It must be. I'm still here to tell you about it.

Xscape is half an hour from York, down the A1 and then M32. Get off at Junction 32 and follow the signs. There are 1,400 free parking spaces. Entry to the centre is free. Skiing or snowboarding lessons cost £26 adults, £22 junior. You can hire clothes and skis, but do take gloves. Recreational skiing is £20 an hour/ £30 for two hours at peak times, £16 and £25 off peak. A half hour session on the ClimbZone wall or Sky Ride, with an instructor accompanying, costs £5.50 adults, £4.50 children.

To find out more about Xscape, call 01977 523000.

Updated: 08:59 Saturday, October 18, 2003