The Skye's the limit

It's theatre, but not as we know it. A Scottish group has installed coloured lights and performance areas around 30 square miles of beautiful island rocks. Paul Taylor takes a guided tour

This event - which takes groups of 200 people on a poetically illuminated midnight hike round a landscape of stunning rock-formations - has not been an easy case of "hey, let's do the show right here". It has taken four years of preparation; it required the compiling of a 300-page planning proposal; it has involved helicopters airlifting pre-constructed lighting and performance platforms onto its dramatic terrain; and it has cost £1m. Nor will it be overly indulgent in its demands on participants. Alan Bennett once said that the trouble with art is that it's so "hard on the feet". And that was just the National Gallery he was referring to. Imagine how he'd react to an art installation where you have to be equal to a two-hour trek up a rapid 1,500 ft ascent at an unsociable hour and are advised to bring walking poles, waterproofs and some midge cream.

When I visited the site, it was a beautiful, sunny summer's day with perfect visibility. Farquhar tells me that I'm honoured because the previous night, they'd done a lighting test and the Old Man of Storr - the 48-metre awesome finger of volcanic rock that pokes up from the spectacular sweep of petrified lava flows, gullies, corries and pinnacles - had remained obstinately shrouded in mist. But then part and parcel of the experience, he tells me, is the atmospheric interaction between the volatile Skye weather and the lighting design devised by his regular collaborator, David Bryant, whose distinguished CV includes everything from Michael Jackson concerts to G8 summits.

He describes the piece, which eludes crisp categorisation, as "a response to the landscape", maintaining that "it's only like theatre to the degree that there is a journey with a start and a finish and that it does fall into a kind of three act structure." Also, though each person is bound to react differently, there'll be a sense of communal ritual. The path is marked out by 4,500 cat's-eyes that bounce light off the walkers' headlamps, which, in turn, create one of the show's most beguiling images - a serpent of luminous dots snaking through the darkness and becoming an integral part of what it traverses.

Mutability is a key theme that embraces the content and aesthetic approach of the event and the ecologically sensitive context in which it has been created. Not only is the geology of these seemingly eternal vistas always evolving, as was powerfully brought home to two of the nva team when they witnessed a 4,000-ton rockfall on to the originally projected route ("If we had done the show a year earlier, it would have probably killed half our staff"). But our cultural relationship to landscape is also subject to sizeable shifts. Mountains may now be considered sublime natural wonders worthy of romantic, life-risking love.

For centuries, though, they were deemed to be eyesores, dismissively characterised by Dr Johnson as "considerable protuberancies". One of the books that have influenced the making of The Storr is Mountains of the Mind, Robert McFarlane's award-winning history of how mountains have shaped us and of how we have shaped mountains, perceiving them through a filter of associations.

The show is accordingly designed to sharpen our sense of the unfolding, non-static nature of rocky landscape and to heighten our awareness that what it "means" to us is a complex, culturally and historically mediated matter. There will be "traces of past lives"; drifting down the mountain, there will be recorded poetry (by the local bard Sorley MacLean and Rainer Maria Rilke), which finds a symbolic sentience in this kind of terrain. A soundscape will include live performance from the Gaelic singer Ann Martin and the aptly eerie and spacious Arctic music of the Norwegian composer Geir Jenssen.

As we gaze out at the rapturously lovely view across the water to the neighbouring islands and mainland, Farquhar describes the scene of what looks set to be the high point of the event. Spread across 30 square miles, there will be three hundred "point source" independent light systems, which can be triggered remotely as dusk descends to create a star-field to rival that of the heavens - "There'll be this strange feeling that the constellations have fallen to earth". It's a gesture that's very characteristic of the project - being at once immensely quick and resourceful on a practical level (pioneering the use, for artistic ends, of technology from the navigation industry that has only come on the market in the past year) and a gentle mix of poetry and politics. "You would once have seen hearth lights burning down there," he points out. "The romanticised landscape where there are no people and no houses is a completely false image. It's bare not because that's 'natural' but because the people were forced off it. So you have a little echo here of the Clearances and the notion of bringing light back and repopulating the place".

Farquhar founded nva in 1992, building on and pushing in another direction the experience he'd gained by devising and performing in site-specific work in Victorian railway sheds, docksides and warehouses as a member of the percussion-based music-theatre group, Test Department. The organisation's list of achievements is impressive, ranging from large-scale environmental animations, to celebrations of light, to the permanent, multi-faith Hidden Gardens in Glasgow. They were invited to Skye because of the resounding success of another high-profile nocturnal ramble, The Path at Glen Lyon. On that occasion, they bragged that they were using enough power to supply a small Highland village. That, though, was located on a working farm. With The Storr, there are drastic restrictions because it is taking place in a very fragile environment that is also a site of special scientific interest. "Every step has had to be broken down and justified," Farquhar announces.

The Storr: Unfolding Landscape, Trotternish, Skye, 1 August to 17 September (01478 613750)