THERE'S something slightly sinister about a field of maize. Stand at the edge looking in, and the eight-foot stalks seem to huddle together, whispering amongst themselves as the wind rustles in the leaves. You half expect one of those tall, spindly aliens from the Mel Gibson movie Signs to be lurking in there, watching you from the shadows. It's enough to make the hairs on the back of your neck stand on end.

Farmer Tom Pearcy grins. "Quite a lot of people say it is a bit spooky," he says. "But nobody disappears and is never seen again!"

We're standing on the edge of his 30-acre maize maze, just outside York next to the Grimston Bar Park & Ride. It may seem spooky to me, but from the distant happy shouts carrying over the tops of the maize from within, it's clear there are plenty of children in there having a great time.

This is the second year Tom has planted his maize maze. Last year it was in the shape of a Viking longship. This year, bigger and better than a year ago, it mimics a giant spider lurking in its web. And it could, Tom believes, be one of the biggest mazes in the world. There are approximately five miles of paths snaking through a sea of 1.5 million maize plants, and covering an area the size of 15 football fields.

Scattered throughout are four strategically located flags - each with a lookout platform where you can stand above the maze and plot your route to the next flag, and a stamping machine which, when you use it to stamp your entry ticket, prints out a quarter of the map of the maze. Get all four stamps and you have a complete map that shows you the way out.

It seems like a great idea for the holidays. Children certainly love it, Tom agrees. Occasionally, some parents become a little anxious, worrying about how long their children will be in there. But he does employ 'searchers' to go and find people who really are lost. "And some parents think it is great. They arrive and say, 'can we lose them in here, please?'"

By now, I'm keen to try it myself. Tom waves me in, and I enter the maze on a wide, red-mud track that is cool and damp underfoot. Instantly, the ears of maize close around me and I am alone. There's a wonderfully green, cabbage-like smell, the rustling of the leaves, and nothing else.

I walk down the path, and take a right at the bottom, where there is a red-lettered sign sporting the words 'way in'. Down there and around a corner, there is an observation platform in the shape of a boat that you can climb to get your bearings. I do so, set my eyes on a distant flag with the number 1 written on it, and set off.

From the platform, it had seemed as if getting to my destination shouldn't be too difficult. But on the ground, the maze seems different from the nice, clean, map-like impression given in the aerial photo. Pathways cross and intersect, leading off round blind curves and more often than not culminating in a dead end. Every now and then a party of children with an elderly grandparent in tow appears around a corner, the children shrieking with excitement. "Have you found it? Let's try this way! Should we follow those people?"

Eventually, after several wrong turns and much leaping up to try to see the flag, I reach Flag No 1 and have my card stamped. There's a pleasant little clearing, a couple of picnic tables, and a tall wooden platform from where I can get my bearings.

A little blond-haired boy is standing up there, pointing excitedly to a path snaking off towards another flag in the distance. "I've found it!" he says, doing a little jig. "You go down there, see that path? You go down there and it comes out... there." He points.

James is six and he's here with his grandmother Hilda Ray, his sister Annabelle, four, and their friend Jamie, ten.

They're having a great time, although Hilda is beginning to look a little tired. They could do with a few more signs, she says. "We've been here now for over half an hour and we've only found one flag. But it is good exercise."

James is impatient. "Let's just go, let's just go!" he shouts, and off the little group troop, leaving me alone again.

Flag 2 takes some finding. It's in a clearing at the heart of the maze; but to get there you have to head off in precisely the opposite direction to the one you think should be right. Eventually, after much doubling back, I reach it and get my card stamped. Again, there are picnic tables, and a tall viewing tower.

Anne Fox is taking a breather, with her two grandsons Joe and Jeremy. "It doesn't seem to be the same when you get down on the ground," she grumbles. "But it is good - and definitely good exercise."

Back in the maze, I navigate more curving paths, bumping into a man who insists the only way to get anywhere is to always take a right, and eventually reach the third and fourth flags. By this time I have a complete map printed on the back of my card, and can use it to find my way back out.

It has been great fun - and it should keep excited children occupied for an afternoon, as well as providing exercise and fresh air.

The maize maze is an example of farming diversification at work. Times are hard and any additional income is useful. 'Agritainment', Tom Pearcy calls it - with, at the end of the growing season in September, the added bonus of being able to harvest his maize crop.

He had the idea when travelling in the United States. Then a couple of mazes sprang up in the south of England, and he thought he may as well give the idea a go. "I've always been into crop circles," says the 32 year old.

So where did he get the idea for this year's maze? "I saw a spider's web hanging on a fence on a dewy morning," he says. "And I thought yeah, that would make a great design."

Not, you understand, that he wants anyone to get trapped in the spider's web. And even if you do, there are always those 'searchers' to help you out...

The York Maze is open until September 21. Access is from the Grimston Bar Park & Ride, admission £3.50 adults, £2.50 children, under fives free.

Updated: 10:55 Tuesday, July 29, 2003