Just down the road from Gatwick, the neatly hedged English countryside gives way to an exuberant, utterly alien-looking landscape. Arable fields are obliterated by dense thickets of sallow. Eight metre-wide blackthorn hedges spill into flowery meadows. Wild pigs and red deer run rampant through ragwort, thistles and other weeds. The air is alive with birdsong rarely heard in Britain today – spectacular bursts of nightingale and the purring of turtle doves.