Countryfile marks the 100th anniversary of Roald Dahl's birth by discovering his passion for the great outdoors and how it inspired his writing. John Craven explores Great Missenden, the village where Dahl lived for much of his life. He meets children's author Piers Torday, who is inspired by both the countryside and by Dahl himself. There is also a look back through the Countryfile archive to the times we have met others inspired by our beautiful countryside, from underwater painters to graffiti artists. Matt Baker has more news on how viewers can take part in this year's Countryfile Ramble for BBC Children in Need by putting on their own sponsored rambles. This year's ramble weekend is Saturday 8and Sunday 9 October. Last year, thousands of Countryfile viewers took part, helping us raise over £850,000 and transforming the lives of some of Britain's most disadvantaged youngsters. With a fortnight to go until Countryfile plays host to the 40th-anniversary edition of the legendary One Man and His Dog sheepdog trialling competition, Adam Henson meets the English and Scottish teams hoping to bring home this year's trophy.