Since the tent is one of mankind's oldest dwellings, perhaps we all carry some deep nomadic folk memory of living close to the elements and moving home from day to day. Why else are children so delighted by that first night under canvas in the back garden?

The delight doesn't always last, partly because of the British weather. But modern tent fabrics and design make it much easier to stay dry, so camping trips in the UK don't have to be the damp experiences they once were. And the countryside's now open after last summer's foot and mouth epidemic.

For many years, most camping in Britain has been umbilically linked to the motor car which carries all the gear. But kit is much lighter and more ingenious these days, and if you leave the car behind and do it on foot there is a whole new range of pleasures and satisfactions. High among those pleasures is probably physical exertion: carrying your gear from place to place will leave you tired, but also fitter and more relaxed.

Everyone has the occasional terrible night under canvas, but there'll be many when you sleep blissfully for 10 hours. Then there is the peculiar satisfaction of self-containment - being free for a change from the complex web of technology which supports modern living but sometimes seems overwhelming. Instead there's just you, your two feet, and the stuff you have on your back.

Cameron McNeish, editor of the Great Outdoors magazine and President of the Backpackers Club, says he finds the problems of life fade away when he goes camping in the Cairngorms in Scotland. 'The more abstract concerns disappear and you focus on simple, tangible things,' he says. 'Where do I find water? Where exactly shall I pitch my tent? Is that a blister I've got coming?'

Another strong benefit is getting deeper into the landscape than you ever can with a car. Some backpackers spend days in the most remote parts of the country, far from roads and houses, surrounded by mountains and moorland. It can be a cathartic escape from the pressures of life.

McNeish says people have all kinds of different reasons for getting away from civilisation into remote countryside. 'For some people, there's even a spiritual content to it,' he says. 'Out in the mountains, I get this sense of the small scale of mankind. It's almost like going back to the womb - a comforting feeling of going back where we came from, among the rocks, the sky, the air and the water.

'There's definitely something very satisfying about being totally self-sufficient, going out there carrying with everything you need for survival. 'With modern technology some people get their pack weight down to about 10 pounds for a single night, and for a long weekend there's no reason you need carry more than about 25 pounds.'

And even the hard bits can be good. If you get your tent up just before the storm hits and lie there nice and dry in your sleeping bag, brewing hot chocolate, you get a sense of smug well-being which is hard to replicate in the humdrum world of the suburbs.

Carrying your own tent also gives you flexibility: you can live outdoors if the weather's right, perhaps even sleeping under the stars on the warmest nights. But if the weather turns really nasty you can duck into a youth hostel, a B&B, or one of the growing number of simple 'camping barns' in national parks and other popular walking areas.

Camping in Britain is not as straightforward as it is in countries such as the United States or Australia, which have huge undeveloped areas where you can put your tent up wherever you like. All land here is privately owned, which means you need to say in a camp site or get the permission of the landowner.

But there is no shortage of rights of way and long distance footpaths (see panel on routes.) Some are challenging mountain treks where you need to be very fit to carry a heavy rucksack, so if you're new to backpacking it would be sensible to start with a lowland route such as the Cotswold Way or the Tarka Trail in Devon.

There are also plenty of camp sites. Many of them cater principally for caravans , motorhomes and big tents installed by people who stay in the same place for several days, or an entire holiday. Such sites tend to be in places with good road access, close to big tourist attractions or popular beaches.

Walkers with backpacks may need to use such places from time to time, but if you're on foot it's possible, with a bit of advance planning and research, to get to areas which can't be reached by big vehicles. Here the sites tend to be smaller and feel less institutional. Some of them will only have a cold tap and basic toilet and charge pounds 2 or pounds 3 per person a night, although others will have showers and perhaps a basic shop, with prices around pounds 5 a night. There are plenty of camping directories in bookshops whose listings include smaller sites, and some helpful websites such as www.campinguk.com.

But the next question is: what do you do if there simply isn't a site in the place you want to be? The best solution is to find the farmhouse and ask the farmer if you can use a corner of a field. Most will say yes, providing you convince them you'll respect the crops and livestock and take your rubbish with you. Sometimes, however, you might be miles from anywhere, on open mountain or moorland, with not a field in sight, let alone a farmhouse.

In this situation a few people do camp 'wild', and landowners or national park authorities often tolerate this and turn a blind eye, providing such campers are absolutely meticulous about protecting the environment and leaving no trace of their visit. Dartmoor National Park has developed a code of practice for this kind of camping. The code says you should get permission if possible, stay out of sight of roads, houses and recreational areas, confine your stay to one night, avoid pitches where other tents have been recently, bury excrement at a distance, don't light campfires, avoid fouling water with soap or waste, and take all rubbish including toilet paper away with you.

Of course you don't have to be constantly on the move when you're backpacking. Camping on foot can be a cheap and enjoyable way to stay somewhere with other activities in mind. There are many sites in mountain areas inhabited mainly by people who spend the days on local walks, leaving their big pack behind. Such areas include Snowdonia in Wales, the Lake District in England, and Glencoe and the Cairngorms in Scotland.

Some sites are often occupied by rock climbers and potholers, such as Rowter Farm at Castleton, near Sheffield (01433 620271). Many backpackers stay for days on coastal, riverside or lakeside sites so they can swim, sail, waterski, surf or go kayaking or canoeing. One site good for watersports is the Cashel Caravan and Camping Site, Balmaha, near Loch Lomond in Scotland (01360 870234).