A seven-mile memorial walkway through London's parks will commemorate Diana, Princess of Wales, it has been revealed.

A fountain will also be built along the route, which passes Kensington Palace where Diana lived for 15 years.

The walkway - costing more than �1.5m - will pass through the Royal Parks - Kensington Gardens, Hyde Park, Green Park and St James's Park. It will be signposted by 70 plaques set in the ground.

Plans were revealed after a Downing Street meeting of the Diana Memorial Committee.

Chancellor Gordon Brown, who heads the committee, said the route would be "one of the most magnificent urban parkland walks in the world".

The walk passes Kensington Palace, Buckingham Palace, where Diana stayed after her engagement; the Queen Mother's residence Clarence House; St James's Palace, where Diana had an office; and Spencer House, the one-time London mansion of the Spencer family.

The Diana fountain, which will not include a statue of the late Princess, is backed by Prince William, 17, Prince Harry, 15, and the Spencer family.

Five possible locations within the four parks are being considered for the fountain, although there is also a proposal for a fountain at Somerset House in The Strand.

Details of the Diana memorial playground in Kensington Gardens are due to be released on Thursday.

The �3m bill for the walkway and playground will be met from the government's 1999-2000 allocation to the Royal Parks Agency, an executive agency of the Department for Culture, Media and Sport.

Both are on schedule for opening on 1 July, which would have been Diana's 39th birthday.