The 20 best places to buy a property in Britain

So, where are these places - and why are they such a good investment? In exclusive research for The Sunday Times, Knight Frank has pinpointed the top 20 fail-safe investment towns in Britain, taking into account factors such as the affordability of housing, wages and unemployment in the area, population growth and how qualified the locals are. It makes for surprising reading: alongside predictable favour-ites such as England's two oldest university cities, there are some less expected, and cheaper, alternatives.

Cambridge, which heads the list, ticks all the boxes. It gets top marks for wages, employment growth and the qualifications of its workforce. Add in the bonuses of a historic city, plenty of employment at the university, Adden-brooke's hospital and the various science and technology parks that have sprung up on the outskirts of the city, as well as restrictive planning laws, and the outlook looks good - regardless of the credit crunch.

"Because there is a limited supply of good-quality property, someone wanting to live in the city centre or close by will pay a high price," says Richard Hatch, a partner in the local office of the estate agency Carter Jonas. "Some people have been waiting for the right house to come along for years, so whether there's a recession or not, they will jump at the opportunity to buy." Admittedly, affordability is not so great - prices rose by 49% between 2002 and the end of 2007, so a Victorian terraced house near the city centre could set you back anything between £600,000 and £1m - but with plenty of London commuters earning good wages, easy transport links and pretty countryside nearby, Cambridge looks set to remain a strong investment.

York, number two on the list, has many of the same things going for it: an attractive, historic town centre, good links to London (roughly two hours by train) and a relatively small supply of housing stock in heart of the city. Added to that is the ease with which you can reach other nearby towns and cities where people might like to work, but not necessarily live. "In York, it is the proximity of Leeds as an outside centre that underpins jobs," Bailey explains. In the same way, prices in Bath, at number nine on the list, are boosted by the ease of the commute to Bristol, Swindon or London.

York also makes a good rental investment, as Andrew and Sara Jackson discovered when they bought a two-bedroom flat in the city centre six years ago. "It's proved an amazing investment - it's never been unlet," says Sara, 40, a teacher at an independent girls' boarding school. The couple, who have five-year-old triplets, have just bought a second property in York: a four-bedroom, Grade II-listed house just opposite the Minster for £422,000, which they plan to let out until Andrew, 43, an army officer, retires.

The city offers another bonus: good schooling. "York has some of the best state and private schools in the country," says Edward Waterson, head of Carter Jonas's York office. "We've had people moving to York from other parts of the country specifically for education," The quality of education is also a plus point for Oxford, number three on the list, according to Damian Gray, head of Knight Frank's office in the city. "The best schools are concentrated quite close in Oxford, and there is only a finite number of houses," he says. "If you're changing your life to put your children through school, you have to have one of these houses."

Such properties are not cheap - a period family house on one of the best streets in central north Oxford will cost between £1.25m and £4m - but people are falling over themselves to get at them. "Even though everyone would have it that times are bad, if you don't step forward, you won't see a house like that again," Gray says. A diverse market, from academics to investment property for students, means Oxford is "fairly bombproof", he adds.

While historic centres and period properties hold their value, cities don't have to be ancient to be a good place to buy. With its concrete monoliths, well-ordered suburbs and sterile walk-ways, Milton Keynes, which last year celebrated its 40th anniversary, has little in common with the medieval glory of York, for example. Yet it has made it into fourth place thanks to its well-planned infrastructure, excellent transport links (it is 40 minutes by train to Euston) and the ease of access to attractive countryside.

"People want to come here," says Mark Johnson, head of sales in Knight Frank's Milton Keynes office. "Everything you need you can walk to, and, although they're putting in flats in the city centre, there aren't enough to feed demand." Prices, at an average of £239,834, are reasonable: a two-bed flat with a private roof terrace within walking distance of the station costs between £200,000 and £300,000. And while Milton Keynes is not a dormitory town full of London commuters, it might soon be, Johnson says. It's a similar story in Telford, Shropshire (number 18), another new town. Average property prices there are just £175,622.

Ease of commuting is an important factor for all top 20 towns.Guildford, in Surrey (number five), is a prime location for those who leave London in search of a better quality of life, but continue to work in the capital. "For those wanting a slightly easier family life, this is an obvious choice without cutting all ties to London," says Tim Harriss, a partner in Knight Frank's Guildford office, who estimates that 70% of his purchasers travel daily to the capital. Again, the good schools attract families and, while property prices are high - a detached family house costs between £800,000 and £2m - young singletons are moving there, attracted by new development around the station, where one-bed flats go for about £150,000.

That range of prices is behind the appeal of other places on the list, such asBrighton, in East Sussex (ranked 13). Nick Cropp, 27, bought a two-bed flat in a terraced period house in the city for £215,000. He works for Plain Lazy, a clothing company based in nearby Lewes, but the properties there did not suit his requirements.

"Because it's bigger, Brighton has a variety of property, so you can choose where to step onto the ladder," he says. "I would like to live in Lewes - but when I'm 32, with kids on the way. It's mostly big old family houses there."

Although most of the places on the list are expensive, Telford and Milton Keynes are not the only cheaper areas where first-time buyers can still benefit from good wages, a high employment rate and population growth. Ports-mouth, in Hampshire (number 16), and Warrington, in Cheshire (number 20), both have strong economies but relatively low house prices: £171,131 and £174,757 respectively, making them the cheapest on the list.

It is not only about jobs, however. Indeed, some places, such asWorthing, in West Sussex (number 11), Bourne-mouth, in Dorset (number 15), and, to some extent, Norwich, in Norfolk (number 19), owe their positions to their popularity as retirement destinations. "People are moving into the area because they're coming up for retirement," confirms Tim Stephens, director of the Norwich office of Humberts. "They don't need to be within an hour and 20 minutes of London, so they sell up in the capital, put some cash in the bank and move here."