Building work is beginning on the Peter Pan playground designed as a memorial to Princess Diana in Kensington Gardens.

Featuring a pirate ship and a wigwam camp, the £1.3m gardens are due to open on 31 July - which would have been the Princess's 39th birthday.

The new playground, close to her former London home Kensington Palace, is a redevelopment of the existing children's facility funded in 1906 by Peter Pan creator JM Barrie.

Work on the children's playground will fittingly be marked by a two-year-old - the son of the project's manager - who will create footprints in wet concrete at the site.

A seven-mile memorial walkway through London's parks will also be built to commemorate the Princess.

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 Diana Memorial 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.

There are also plans for a Diana fountain to be built along the walkway.

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

The £3m total bill for the walkway and playground will be met from the government's 1999-2000 allocation to the Royal Parks Agency