new neolithic art

Rocks of ages

Richard Long walks the remote corners of the Earth, leaving subtle traces of his passing. His monuments are tiny, but they have the power of Stonehenge, says Jonathan Jones

The path is a wet green line across the frosted field. Someone else walked this way this morning, looked at the same view of mountains suspended in the distant mist, and perhaps, as I do, mistook the telephone wires in the frozen sky for a vapour trail. Here in the Welsh hills, the art gallery I visited in London just before Christmas seems a long way off.

But then, it must seem a long way off to Richard Long, too, when he is walking across some far-flung desert. When I saw his exhibition he was around, somewhere, finishing a mud drawing, but all I saw of the artist was a pair of shoes removed and neatly placed on the ground while he splashed wet mud on the walls and moved about chunks of mossy tree bark. I feel closer to him here, in the cold white field that bows upward like a tarpaulin filled by a gust of wind, than I did in the gallery. Maybe the best way to review a walking artist is to take a walk.

At Haunch of Venison in London, the man who has for nearly four decades made an art of walking is showing photographs, texts and two huge drawings made with mud; the ground in front of the biggest mud-work is covered with a grand semi-circle of bark. The brown splashed riverine earth on the wall has a caked pleasure, and just to look at the mass of gnarled objects on the floor makes you feel as if you were walking on uneven stepping stones across a river. This veteran of the dematerialisation of the art object gives you plenty to look at. Since the 1960s, when he started on his path while still a student at St Martin's, Long has imposed a particular cool look on all his presentations of artistic self.

And yet all these works have the remoteness of someone else's souvenirs. They refer to fun had by somebody other than you, somewhere far from here. You find yourself envying the man who made the art, or rather, who had the experiences of which the art is a mere trace.

It's one thing to stand in the middle of London looking at a photograph of a kayak on a muddy strand close to which Long has set up his sloppy blue bivouac, on the shore of a gliding aquamarine river. It would be a lot more interesting to have taken the journey this photograph documents: Six Days by Kayak Down the Columbia River, Washington and Oregon, 2003. In 2004 Long hiked 15 days in the South African Karoo; in 2005 he hiked nine days in the mountains between Galicia and Portugal. I know because he tells us in photographic works that document not only the barren and lovely landscapes of these underpopulated places but the temporary and tactful monuments the walker made to his passing: a cross of stones and foot-scraped earth in the Karoo, a stone circle in Galicia. The photograph of the stone circle looks for a second like a megalithic structure in a clearing in a forest, photographed from the sky; it is really a small ring of pebbles surrounded by grass.

I don't see why artists should have all the fun, so I decided to ponder the art of Richard Long in the open air, far from the madding crowd, on a gelid day at the end of the old year. That green streak of a path across the iced field is impossible to date. Was it made by walkers recently, or does it mark a trail 1,000 years old? Everything here, just over the hill from a Welsh seaside town, is suddenly timeless. Hedges bristle in the cold, red haws glow and, as you walk past the chilled spiky walls, the blistering midwinter sun creates a strobe effect through the dead brambles: the road ahead flickers. You gingerly put your foot on a puddle just to check, and yes, it is frozen solid. I remember, at a festival in Hoxton, east London, a stall selling Richard Long's bags of River Avon mud. Today this Welsh mud is hard; you can walk on it without getting your shoes dirty.

The path over the field follows the course of Offa's Dyke, the great earthwork built by a king of Mercia in the eighth century to define the boundary between Saxons and Celts. Long is an evangelist, of course. He walks in the spirit of a medieval pilgrim. He believes - he must do - that by walking the earth you understand it more fully. And even my brief walk tells me this is true.

Clambering down a slope at the end of the field, you stumble through the trees and on to a roadside; up the lane in the distance is a hill with a curiously artificial-looking summit. This is the target. Walking close to the hedge, you sink into the landscape, as the view vanishes and the lane embeds itself deep between massive earth banks, and suddenly you're by a main road, on which trucks are roaring westward. The unreal hill is closer now, its sides clothed in fir trees, surely a modern planting. There's a sheep farm ahead, and above it the woods part to reveal the object, hidden from every direction except one, that gives the hill its unusual character: an earthwork, evenly shaped, very big and round and smooth, and looking out towards Ireland. The Gop hill is capped by a prehistoric structure whose function and exact age have never been determined. A cave in the slope below it was a Neolithic burial chamber. The cairn itself is probably Bronze Age. Excavations have never discovered anything much inside.

It gets me to what I really like about the art of Richard Long. In his photograph titled A Circle in Galicia, Long makes his affinity for prehistoric culture explicit. This is the elusive heart of his enterprise. Wherever he walks, he makes some subtle mark. These impermanent sculptures, known to others only through photographs and gallery-bound secondary works, more often than not take the form of stone circles - however tiny, however casual. In the past few years, in walks documented by the Haunch of Venison show, he has made a stone circle on Mount Parnassus in Greece, a circle of herd droppings in Mongolia, and an arrangement of megalith-like rocks in South Africa. The Greek circle was made in 1999, the text on his photograph announces, and "dispersed" in 2002.

Long is one of a generation of artists in Britain and America who not only chose to work in landscapes where no art gallery could possibly exist - and rejected the idea of a unified commodifiable artwork, seeking instead to make an impermanent, changing, decaying art inseparable from its (remote) place - but who took inspiration from the ancient monuments of megalithic Europe rather than modern traditions of landscape depiction or abstract sculpture. These monuments are the earliest architecture human beings made anywhere, and they will never be completely understood. Archaeologists wonder if the henges and barrows and mounds were temples, or sundials, or calendars. Artists see that, more than anything else, they are responses to landscape. You only have to visit one of these places to realise that the early Europeans shared our love of just looking around, for no art is more sensitive to place. Stonehenge is a great navel under the empty sky of Salisbury Plain; the landscape, marked for miles around with tombs and pathways, seems to revolve around this circular hub of the wheeling cosmos.

Long is comparatively modest in his neolithic aspirations. American artists who share his interest in space and time have famously recreated ancient art on a Stonehenge scale: James Turrell claims direct inspiration from the Stone Age for his natural observatory in a crater outside Flagstaff, Arizona, and the colossal dimensions of Robert Smithson's Spiral Jetty in Utah make it one of the post-1960s works that will always capture imaginations. Long has, for nearly 40 years, made a gentler, more English, yet equally romantic version of this new Neolithic art.

The creators of the Gop cairn are nameless, their creation an unsolvable enigma. In the West End, Long mixes primordial mud in a plastic bucket. As I walk back over the hill, art at the beginning of the third millennium suddenly seems rooted, after all, in necessity and nature. As Jacob Bronowski said, other animals are part of the landscape; only we have shaped the landscape. And that doesn't have to be a violent or an ugly act. Long knows what the makers of the Gop cairn knew: it's only human to leave something behind.