WHEN a psychedelic Florence and Dougal are waving from the walls of the dance floor, when a red and green maze flashes different colours and the dry ice prevents you from seeing beyond your outstretched hand, you know it was worth packing your party duvet and driving 300 miles to Doncaster. Yes, Doncaster, land of pits and pit closures.

Our hosts, Jack and Dennis, spend the week at home, helping their father to make three-dimensional wooden jigsaws, but on this Saturday night their parents were away and they were throwing a party for 100 or so friends.

The doors opened at 6pm on Friday, when a few of the hard core turned up in Kombi vans, ready to settle in for the weekend; they would probably be staying until Monday morning. The remainder arrived in sporadic groups, from all parts of the country, throughout Saturday.

By the time we arrived at 8pm, in a car rattling with empty beer cans, Jack and Dennis had mixed a black dustbinful of punch. 'It's probably a bit rough,' said Jack. 'It's full of cider, brandy and something that doesn't really deserve to be called gin, more spirit with juniper berries.' Dennis took a beakerful. 'I don't think there's a strong enough kick,' he muttered knowledgeably. So we set off again into the fog, along a maze of mud tracks, in search of an off-licence. When we found one, the owners could not believe that they were managing to shift the two dusty bottles of Napoleon brandy from the top shelf.

Back at the house, the Goa posse were setting up the drapes and sorting the sounds. Dressed in luminous clothes, their dreadlocks topped by woolly hats, they tacked the hand-painted sheets to the walls of the dance floor, while others wired up the turntables and strobes. In the centre of the room, they erected a juggling platform. The dance floor was upstairs past the sleeping alley, a corridor of beds squashed together, where those who could not stand the pace would eventually crash out.

Downstairs, the party was already beginning. The pizza van arrived with about 30 boxes to sate bad cases of snack attack. The van, which had been stuck in the mud, was eventually push-started by some hippies, skidding around in the dark, their fluorescent trousers aflutter. Another group was tucking into the fortified punch. 'Not bad,' said a boy in a striped shirt. 'It doesn't taste too alcoholic.' He was later seen fast asleep underneath the beds in the sleeping alley.

At about 10pm, a circle had gathered around the black dustbin. Each person called out a number in turn: 'One, two, three, four, five . . .' 'You drink,' shouted a boy, pointing at the next person in line: a girl with long blonde hair and a blue hat. 'Why?' she protested. 'Because those are the rules,' he said. 'Oh, OK,' she replied, knocking back the cocktail and reeling out.

Upstairs they pumped up the music and filled the room with smoke. DJs took it in turn to spin the decks, the music ranging from ambient techno to acid jazz, each genre attracting a different group. Gabriel from Russia, in a pair of African tribal trousers, was in an altered state, dancing in swirls of smoke, staring at the spirals on the wall. Lennie, in a long, tight red skirt with a brown, flat stomach, wove around in circles, while Toby and his bouncy curls gyrated manically on the spot.

Other parts of the house offered other atmospheres: the chatting room, the smoking-and-drinking room, the relaxing room, the too-drunk-to-speak room.

As the sun was rising, the party moved outside to watch the juggling of silver fire sticks. Inside, a long-dreadlocked DJ was playing Goa acid music.

Come 11am on Sunday, most of the revellers had quietened down. Some had not slept; others wished they hadn't. The only problem, apart from sharing three tea-bags among 50 people, was negotiating the 300 miles home.