The post-war idyll of England's peaceful green and pleasant land is fast fading into the history books.
Images of pastoral retreats, Hovis-style villages disturbed by the rattle of a bicycle and clear skies echoing to nothing more than bird song are under threat.
According to new research by the Council for the Protection of Rural England, oases of peace have shrunk over the past 30 years to only three major areas of rural tranquillity.
In new maps issued by the CPRE, the three large remaining "reservoirs" of tranquillity are in north Devon, the Marches of Shropshire and Herefordshire, and the Pennines.
The parts of England which remain free from urban blight, noise, pollution and overcrowding are estimated to be four times smaller than in the Sixties. Over the past 30 years an area of tranquillity the size of Wales has been lost. The CPRE says industrial development, new roads and increasing traffic have left the countryside "shattered".
The research is the most recent attempt to measure "quality of life" factors once regarded as unquantifiable, but "environmental evaluation" is now acknowledged as importantenough for the Department of Transport to carry out a noise and air pollution study.
Tranquil areas are a planning tool developed for the CPRE by the ASH consulting group to replace the simple split between rural and urban areas which is regarded as too limited.
Tony Burton, the CPRE's senior planner, said : "The built-up areas of England represent 17 per cent, but the disturbed areas represent 50 per cent. It is crucial to acknowledge that development goes far beyond the physical boundaries of brick and concrete."
Tranquil areas are defined as places beyond the immediate influence of towns, roads, airports, overhead pylons and mining.
Examining the shrinkage over the past 30 years shows, for example, that in the South-east, the reasonably intact countryside surrounding London in 1960 has completely fragmented. The CPRE blames a fourfold increase in road traffic, air traffic, new developments and the rise of the National Grid. It estimates that it requires 150 miles travel from the capital to reach an area of tranquillity.
The South-west, formerly England's most tranquil area, is breaking up fastest; East Anglia is "fragmenting"; while the North-east is the least changed since the Sixties.
Jonathan Dimbleby, president of the CPRE, said the erosion of rural peace demanded action. "We are on the brink of losing tranquillity forever across much of England. The message of these maps is that we need an urgent reassessment of priorities if we are to avoid consigning tranquillity to our memories and the history books."
Tranquil areas are measured as ...
4km from a power station
3km from major motorways, large towns and major
2km from major trunk roads and the edge of smaller towns
1km from busy roads and main line railway lines
beyond military and civilian airfield noise
beyond sight of open cast mining