South Downs

The South Downs National Park was created in 2010 in southern England, across Hampshire, West Sussex and East Sussex, and protects some 1,627 km². It is the most recent of the English national parks and the most densely populated, with more than a hundred thousand residents within its boundaries and millions of people living a short distance away.

Its foundation is chalk: a band of soft limestone laid down in a Cretaceous sea that forms rolling hills and ends abruptly at the English Channel in the dazzling white cliffs of the Seven Sisters and Beachy Head. On that rock develops chalk grassland, a calcareous sward of very low fertility that can hold forty or more plant species per square metre and a butterfly and orchid community that is exceptional in western Europe.

That habitat depends entirely on grazing: without sheep the grassland turns to scrub and loses its richness, so conservation means maintaining extensive livestock farming that the agricultural economy does not always sustain. The park also includes ancient woodland, heaths on sandstone and the South Downs Way, a long-distance path of more than a hundred miles that crosses the whole park from east to west.