Barton Hills National Nature Reserve - "The reserve has a large population of the rare pasque flower and several other rare plants are present in the downland, including greater pignut and fleawort. There is also a range of characteristic chalk grassland plants such as wild thyme, horseshoe vetch, marjoram and rockrose, and a good show of orchids in summer." "There is an attractive level walk along Barton Brook on unsurfaced paths. Other than that, Barton is very hilly and there are steep gradients" - from the Chilterns Conservation Board website