Yorkshire’s open-air gallery is not just good for a day out; James Turrell’s “skyspace”, set within its grounds, puts public art in a whole new light.

Ah, the great outdoors. For a city dweller, the countryside offers the one thing in short supply in the metropolis: space. And when it comes to space, Yorkshire Sculpture Park has acres of it – 500 rolling acres to be precise, a rural landscape dotted with 60 sculptures and a herd of sheep that gently nibbles the grass at the base of such bronze luminaries as Barbara Hepworth’s The Family of Man or Henry Moore’s vast reclining figures.

It is perhaps this sense of space, and of the changing Yorkshire light as it hits lake, tree and parkland, that caught the imagination of sculptor James Turrell. The American artist has spent almost 40 years turning a 600 foot-high extinct volcano in the Arizona desert into a work of art – he hopes the steep, conical hillside will one day act like a giant naked-eye observatory – and who has spent a similar amount of time creating “skyspaces” in locations across the world.

He’s spent almost 40 years turning a 600 foot-high extinct volcano into a work of art

Yorkshire Sculpture Park is one such location. Turrell visited the park in 1993 and decided to create a “skyspace” there; it wasn’t until 2007, however, that The Art Fund stepped up to pay for the commission and turn what was a disused deer shelter into a work of art. If you’re unsure as to what, exactly, a “skyspace” is, it’s fairly straightforward. In this case, it was the transformation of the Grade II-listed shelter into a room with white-plastered walls and plain concrete benches ranged on three sides. A hole in the roof was punched out, its clean rectangular shape framing the sky above. And that’s all there is to it; it is monastic in its simplicity.

Of course, Yorkshire can’t claim to have one of the best, first or even biggest such skyspaces. They are scattered across the globe, from Ireland to Spain, via Israel, Japan, Switzerland, Germany and Australia. But the one that sits within the grounds of YSP feels particularly English. Barely troubling the surface of the hillside into which it appears deep set, its sides forming part of the grassy landscape and with the occasional sheep nosing inside, it is a modest affair. All it allows you to do is look up – in wonder, at the light, at the clouds or blue sky, or at stars as cleanly brilliant as the artwork below.

James Turrell was brought up a Quaker; his grandmother advised him that during the long Quaker silences he should “go inside to greet the light”. She had loftier ideals in mind than the aesthetic ones James went on to develop, but she was on to something. Light, space, time to stop and think: with its 500 acres and this – the Deer Shelter Skyspace – Yorkshire Sculpture Park offers just a touch more than you might suppose the great outdoors could supply.