Art review: Jupiter Artland

• Cornelia Parker's Landscape with Gun. Picture: Neil Hanna

JUPITER Artland is in the grounds of Bonnington House, a few miles to the west of Edinburgh. It is called a sculpture garden, but that doesn't do justice to the scale of the project. Covering 80 acres, landscape garden would be a better description. This remarkable project was undertaken simply for the joy of it by Robert and Nicky Wilson. They live in the house and are bringing up a young family there for whom the sculptures make an amazing playground.

Immediately after you enter you pass the first work, a wood of young sycamore trees, each one coppiced so it has several trunks and cradling between these trunks are massive rocks, their size emphasised by the fragility of the young trees that support them. This is Stone Coppice, an unsettling work by Andy Goldsworthy. Then you literally drive through a huge land-form designed by Charles Jencks with ponds and banks and spiral mounds. On the horizon beyond this is an enormous figure by Marc Quinn.

Most of the sculptures are in the woods behind the house, however. They are all big, but Anthony Gormley's is the biggest. His subject always is himself, but this must be his largest ever self-portrait. Mounted on a hill top at the edge of a wood and constructed from an open network of steel girders, it is an enormous figure bowing down as though in homage to the industrial landscape of West Lothian's giant shale bings and the Forth Bridge visible in the distance. There is also another major work by Andy Goldsworthy here, Stone-House-Bonnington. This looks like a small barn built of local whin stone, but open the door and inside, instead of a floor, there is native bedrock. The soil has been scraped away to reveal the rugged rock, the very bones of the landscape.

Nearby, Suck the Neck is an extraordinary work by Anish Kapoor that also opens to the earth beneath the landscape though in a much more sinister way. A huge steel cage encloses a hole in the ground, shaped like the mouth of a vortex and plated in cast iron. You feel the cage is there, not to keep something in, but to keep you from being sucked into the dark hole and down to an unknown underworld.

Ian Hamilton Finlay was central to the inspiration of Jupiter Artland. Fittingly he has more works here than any other artist. Mostly installed before his death, they go back to the beginning of the project. There is a set of his Beehives, for instance, while Only Connect turns the last line of EM Forster's Howard's End into the physical metaphor of an elegant stone bridge over a ditch. The Temple of Apollo is a small, circular stone temple. Inside on the inner surface of the pediment is inscribed a typically enigmatic quotation from Finlay's favourite inspiration, the French Revolutionary St Just: "Consecutive upon Apollo a titanic revolt in his heart."

Beyond the temple the bust of Sappho stands on a pedestal. The tenth muse, she is described as "the poetess of erotic lyricism and the symbol of love and beauty," but when I was there, the concerns of Robert and Nicky Wilson were more mundane. They were puzzling over how to stop people ploughing a path directly from the temple to the muse.

That is typical. They are very hands-on and this is very much their project. Indeed as she took me around, Nicky Wilson showed me a length of embanked path she had built herself. It looked very well constructed. Nearby, the wood seems to be haunted by the ghostly figures of a number of young girls scattered through the trees. In white painted bronze, they look like a scene from The Turn of the Screw rendered in sculpture. This is a work by Laura Ford. The girls look as though they might be playing hide and seek, but actually they are having tantrums. Beneath the surface, in the quiet woodland hysteria lurks.

At one point as you look out from the wood across the fields, you see the view through a giant web suspended between two trees. his is Over Here by Shane Waltener. It links the woodland to the wider landscape. There have also been other more ephemeral works. When the garden opened for the first time last year, for instance, Cornelia Parker scattered moondust across the estate from a firework and called it Nocturne in homage to Whistler and Debussy.

For the second season, the Wilsons have added five new works. Jim Lambie has made a temporary piece called Zobop (which I didn't see) and A Forest, a dramatic permanent installation. A stainless steel wall, its shiny surface reflects the surrounding woods, but the steel is in sheets layered like paper. The undersides are enamelled and the corners are then folded so that these brilliant enamel colours show like the layers of a Victorian petticoat.

Nathan Coley's In Memory is a strange, rather spooky graveyard of reused gravestones. The names of those originally buried beneath them have been deleted; that, with the status of the gravestones themselves removed from any meaningful context (though not by the artist himself) makes the whole business of the ways in which we seek immortality through our memorials seem remarkably puny. This imitation graveyard is set inside a high concrete wall with a narrow entrance like a prison cell. A soliloquy on death, it all feels rather lugubrious, but that is probably the intention. Peter Liversidge has made Proposal No 47, but it hasn't materialised yet. Not all of his proposals do.

The most striking of these new works is Landscape with Gun and Tree by Cornelia Parker. She has made a replica of a shotgun nine metres high in steel and rusty iron. It leans against a tree, its barrel cradled in the upper branches as though a giant had casually left it there, gone away and forgotten it. The iconography of gun and tree invokes the long tradition of sporting portraits. The model is Robert Wilson's own gun and so obliquely, it implies his portrait.

That is fitting. This brilliant project is a personal adventure for the Wilsons. Their taste alone has shaped it; that, together with the scale and the way the works inhabit the countryside, make this much more than an ordinary sculpture park.

Being shown around by Nicky Wilson what impressed me most of all, however, was her transparent delight in the whole enterprise and her excitement at what they have succeeded in creating. Her enthusiasm is infectious, too, and so I have no doubt at all that it illuminates the ambitious education programme that the Wilsons run for schools throughout the year through the Jupiter Artland Foundation.

The garden is open to the public during the summer, though to protect the landscape and to preserve its sense of privacy, numbers are limited. It's first come, first served, so book now.

Jupiter Artland is open Friday to Sunday from 14 May until 27 June and Thursday to Sunday from 1 July until 12 September. For more information and to book, visit www.jupiterartland.org