The campaign is being run by the Council for the Protection of Rural England and the Dry Stone Walling Association. ``They were built to last by people who have long since gone," Jonathan Dimbleby, the council's president, said.
``It seems inconceivable that tomorrow's landscape will be bereft of dry-stone walls but unless we take action now, that is what will happen.''
A survey by the Government's Countryside Commission found that in the past 50 years 4,500 miles of dry-stone walls had been destroyed by development, road building or, in some cases, by being dismantled by farmers to provide decorative stones for rockeries.
The modern countryside lacks the labour to repair the walls, and the commission estimated that only 4 per cent of the total length was in pristine condition.
The walls are in the west and north of England, in hilly and mountainous areas where plenty of rock was available, where the soil is thin and the climate is too harsh for hedges to prosper. North Yorkshire, Cumbria and Cornwall have 32,000 miles between them - nearly half the nation's total length.
The campaigners want people to gather information about the state of dry-stone walls in their area. They are calling on the Government to increase its grants to farmers to maintain and restore their walls, and for the grants to be offered over a wider part of the country than at present.