So what makes the South Downs so special? To most people the South Downs means one thing - a long ridge of chalk close to the south coast near Brighton. But the landscape is a lot more subtle and diverse than people imagine.
The chalk ridge is all that remains of a once more extensive crown of chalk that covered much of south-eastern England 65million years ago.
Subsequent erosion scoured away the central portion -The Weald - and left two ridges - the North Downs and the South Downs.
Through the work of English Heritage and the National Park Authority there is a much stronger awareness of the fragile nature of the landscape and the importance of defending it for future generations.
When we look at the South Downs, we are not looking at a 'natural landscape'. It has been shaped by human activity over millennia.
Damage during the 20th century
The high downs of the National Park are well-known for their sheep pasture - something that developed in the medieval period - but it is another sort of farming that has had the most significant impact - arable cultivation.
The plough has shaped the South Downs as we see it today but it is important to realise that this sort of farming has had a long history here, starting in prehistory and continuing until the present day.
The impact of cultivation on archaeological features can be serious but it is obvious that the most long-lasting damage occurred in the middle decades of the 20th century.
Deep ploughing
Much of the high downs and surrounding landscape was deep-ploughed at this time with such intensity that many ancient features were erased forever.
But all is not lost. Working in partnership with local farmers the most serious impacts of modern land use are being lessened. Cultivation can be used to encourage biodiversity but it is important to make sure that this takes place away from known archaeological sites.
Converting arable fields to pasture also helps preserve important historic sites and the case study of Park Brow illustrates this perfectly.
