With its unique combination of country house gardens, rolling agricultural landscape and state-of-the-art galleries, Yorkshire Sculpture Park provides the perfect setting for Andy Goldsworthy?s distinctive ?land art?. His work is an intriguing blend of the natural and the artificial. He manipulates organic materials, often in their natural habitat, but in consciously artificial ways. Many of his creations are intrinsically ephemeral, recorded for posterity through photographs rather than tangible artefacts. This exhibition documents some of his past projects, but the core of the show is a series of site specific installations, some indoors, others dotted about the estate.

Mr Goldsworthy?s sculptures range from fragile fabrications of leaves and twigs to quasiarchitectural constructions built from stone and wood. Here, he has created several large ?landscape interventions? called Hidden Trees: drystone wall enclosures encasing the trunks of fallen trees. Built in the ha ha, they exploit vernacular construction techniques in decidedly 21st-century ways.

This is not his first collaboration with the Yorkshire Sculpture Park. As artist in residence in 1987, he created a series of exquisite temporary sculptures from, and in, the landscape, inspired by the changing seasons: an igloo of ice shards in winter, a circlet of freshly plucked blades of grass in the spring, a curtain of red sycamore leaves in autumn. Where 20 years ago Mr Goldsworthy was regarded as an artistic maverick, a pioneer of the emergent (but decidedly alternative) genre of ?environmental sculpture?, now he is globally renowned. His eco-sensitive creations, melding sculpture, craft, photography and performance art, have influenced many younger practitioners, and seem more pertinent than ever in the current era of climate change.

Yorkshire Sculpture Park, too, has moved up a gear over the past two decades. Its impressive new grass covered Underground Gallery, opened a couple of years ago, was carved out of the earth in the centre of the historic walled bothy garden. The Longside Gallery, located on the hillside a mile away, has a glazed end wall giving panoramic views over the park. So art appreciation can be combined here with physical exercise, although a shuttle bus is laid on for those short of breath or pressed for time.

Marking its 30th anniversary, ?Andy Goldsworthy? is the organisation?s most ambitious project to date. The show, which runs for nine months, takes advantage of the entire site. Four installations in the Underground Gallery provide the centrepiece of the exhibition. Exploring pivotal motifs holes, cracks, cones and screens they address recurrent themes in Mr Goldsworthy?s oeuvre, but on an unprecedented scale. One room is colonised by large domes made from stacked slates, each with a mysterious black hole in the top. They suggest ancient burial mounds or portals to another world, bulging outwards from wall to wall. By contrast, the second gallery appears completely empty. The walls are coated in wet clay, which cracks as it gradually dries out. The colours and textures are appealing, but there is a hint of danger, too, in the graphic evocation of drought.

A large cone-shaped chamber constructed from heavy branches dominates the next interior. The mood shifts again in the final space. An ethereal lightweight screen woven from chestnut stalks is suspended miraculously in the centre of the room. The screen is pierced by a large circular hole, conjuring up an absent tree trunk perhaps, or maybe a full moon. Goldsworthy?s holes as with his art in general are open to interpretation. In this show, he takes us on a journey, both literally and metaphorically. ?Andy Goldsworthy?, Yorkshire Sculpture Park, Wakefield (01924 832631; www.ysp.co.uk) runs until January 6, 2008