There's hardly a square foot of land in Britain that somebody doesn't own -and that somebody else hasn't got plans for. Finding room for vital new cities and industries means something has to go. How much countryside will there be at the end of this century when another 15 million of us have been squashed into it?
From the air the progress of this new Battle for Britain is even clearer. This film looks at some of the casualties so far. It features a Bird's-Eye View of the 250-mile Pennine Way which passes through much of England's most striking countryside - and through almost every kind of danger that threatens it.