It is the place where Churchill serve the two districts, from this place one can control the Distt Dir, and District Swat, Malakand Agency is also adjacent here, in fact you have taken the picture of DIR standing in Malakand Agency.
He wrote hundred plus books in his life, his first book was "the People of Malakand", and one of the book is "The Malakand field force" you can find the books on amazon.com