Struck by a bolt of ingenuity

The mind of man and the workings of nature come together in 'Lightning Field', encouraging viewers to discover its layers of meaning.

Only six people are allowed to see it every day and only for six months of the year. It is thousands of kilometres from the big art scenes on either coast and hours from the nearest city. Photos are not allowed, so it barely even circulates in pictures. There is a tiny chance that, if you don't follow instructions, it could help you wind up dead.

And yet, for many of the few who have made the pilgrimage, it turns out to be "one of the great works of art of the last century". That was the judgment of one art-historian friend, not usually prone to hyperbole, when he returned from a summer visit to Lightning Field, a huge work of "land art" hidden in the middle of New Mexico. His rave got me to go.

A classic patch of sagebrush-covered land set on an empty plateau 7,200 feet high. A ring of jagged mountains at its edges, out-cliché-ing any Hollywood western. And in the middle, 400 lightning rods, custom-made from stainless steel and laid out in a grid that stretches a mile in one direction and a kilometre in the other. Set 220 feet apart, the rods tower to several times the height of a tall man; whatever kind of mound or furrow they get planted in, their tops all reach to the same table-flat height.

The work was built in 1977 by a New Yorker named Walter de Maria, then 42, who got his patrons at the Dia Art Foundation to buy the land and commission its conversion into art. De Maria and his work are famous in the art world. What seems strange, once you have visited his masterwork, is how they could be so little-known outside of it.

Lightning Field kept me looking and thinking for longer than I have ever spent with any other work of art, at least all in one stretch. I wandered the site non-stop from afternoon to night of one long summer day and then from before dawn to almost noon the next.

I lucked out. There were evening thunderstorms the first day I went and the mountains all around were bright with lightning, although no strikes hit the rods while I was looking - you are not supposed to be out among them, anyway, when a storm is right overhead. (De Maria chose the area partly for its electrical storms, which occur on something like 60 days annually.)

The piece looks great by storm light, when it is likely to give as many goose bumps as the Sistine ceiling. But the best thing about Lightning Field is that it seems to work at least as well by any other kind of light, at almost any moment that you come across it.

There is no single Lightning Field - that name is the one false note in the whole piece. Every time you look at it, this work feels new and acquires meanings you hadn't thought of earlier. Its central virtue may be that, unlike almost any other artwork you could name, it doesn't have a single central virtue.

It is good that Lightning Field provides so much to see. Because getting to see it is a chore. You had better book months in advance if you want to visit on a day that fits your schedule. Your overnight visit will cost you $250 - non-refundable - which can be paid only by cheque to Dia, which still owns and tends the work.

From the Albuquerque airport, you have a three-hour drive ahead of you, south and west to the tiny town of Quemado (population 324), where you need to be by 2.30pm. That is when Dia caretakers pile visitors - never more than six at a time, by order of the artist - into a muddy 4-by-4 for an hour's winding drive across rural roads.

Eventually, you are dropped off at a vintage log cabin, the site's original homestead, that is even more John Wayne than the landscape around it. You will be driven out the next morning at 11.

You drop your bags, walk out of the back door, and you are in a work of art, as you have never been before. Ideas pile up.

Thought 1: The long trip was necessary. De Maria's piece is clearly about the West, so it is only right that there should be some kind of trek to get you to your destination. That is why the log cabin also feels so right. If you stand in the no man's land between the cabin and the field of rods, you can go from looking "back" at the homestead and the region's past and "forward" to de Maria's version of its future.

Thought 2: The future seen in Lightning Field is truly "futuristic". Look at the rods, with the landscape as the backdrop and you could swear they are a Hollywood special effect. Those crisp poles, with their slick reflections, hard shadows and regular grid, are just the kind of thing most easily rendered in computer-generated imagery; stand among them and it feels as if you have been green-screened in. Back in the 1970s, Lightning Field already predicted how the 21st century would construct a vision of future worlds.

Thought 3: Or this could be absolutely now, anywhere that surveyors grid up open land for subdivisions.

Thought 4: Who said modern art killed classic beauty? The sun starts setting, God's clouds and de Maria's rods are lit deep pink and the Romantic Sublime takes over. Turner, eat your heart out.

Thought 5: Art doesn't get more minimal and rigorous than this. With the sun behind a cloud, the rods become a never-ending grid of identical grey lines. For a moment, aesthetics disappear and there is no room for arty histrionics. All that matters is the statement of a concept: a ground plane. A line rising from it. A space. Another line. Repeat.

Thoughts 6 through 99 and on: With its endlessly receding avenues of rods, Lightning Field is the latest riff on classic Renaissance perspective (try Googling "isocephaly"). Or this is art that sets itself apart from anything that has ever been made.

Lightning Field is about framing the landscape, so you understand it better and differently. Or it is the classic man-made denial of nature, using geometry to cancel out irregularity. It is brutal, all about the threat of death and nature's heedless wrath. Or it is as humane as any masterpiece could be, out to fill whatever uses we can put it to.

It is clear the experience is about as great and powerful as anything could be but does that alone make Lightning Field an absolutely crucial work of art? The very greatest works, such as the best pictures of Titian, Manet, Cézanne or Picasso, leave you puzzled and even risk repelling you. Just as you think you have "got" what they are about, you are left feeling that you have somehow missed the point or that you are simply dumber than they are.

That is almost the opposite of what happens with Lightning Field: As you bounce from reading to reading, you feel each time that you have got the piece just right and all tied up, before you move on to the next instant of opposite but equal certitude.

This feels like what can happen when you are looking at nature. A great sunset may trigger thoughts of everything from the vastness of the universe to the brevity of human life but we don't really credit the sunset itself for the ideas and feelings we have. We own sunsets and deep inside we take credit for their smarts.

Maybe that means that the almost-natural experience of Lightning Field, however rare and wonderful it is, risks leaving us feeling too fine and wise for our own good.