This nature reserve lies in the Cudham Valley and is about ' mile from Down House (Charles Darwin's former home). It forms part of the Downe Bank and High Elms Site of Special Scientific Interest and comprises ancient woodland, known as 'Hangrove' and a chalk grassland clearing that was called 'Rough Pell' on the tithe map of 1840.
Downe Bank is a uniquely special nature reserve, due to fundamental scientific studies carried out by Charles Darwin which were eventually published in "Fertilisation of Orchids". In summer at this reserve, some eight species of orchids flower, along with carline thistle, rock rose, marjoram and wild basil.