The Mill Field is a 3.4 hectare Site of Borough Importance for Nature Conservation, Grade II, in Mill Hill in the London Borough of Barnet. It is a public open space which slopes steeply down from the road called The Ridgeway. It may be the site of the windmill which gave the area its name. This was documented as early as 1321 and had disappeared by 1754. More information on the Wikipedia page [1]