One of the "family adventure walks" Emma, the boys and I took was this one which began at Little Missenden in The Chilterns. Roald Dahl lived in this area and the walk includes a visit to his home and studio where he worked. We didn't visit his home but did take a magnificent walk through the village and surrounding countryside. Here is the beginning of the walk in what was described in the book as an "ancient path". As you can see it has extremely high sides. Emma, can you find out any more on this path? I've tried through Google but nothing - although there were a number of wonderful looking books on walking in the Chilterns.
