John Craven visits the remote and strange landscape of Crummack Dale in the Yorkshire Dales. Here he learns about the Norber Erratics - giant boulders scattered after the last ice age, which have inspired painters, poets and dancers. And in a Countryfile exclusive he witnesses the first ever release of captive bred native crayfish anywhere in the UK.Ellie Harrison is in Kent, discovering the old industrial sites that are amongst the best nature reserves in the country. Tom Heap investigates whether our love of foraging is threatening the countryside. And Helen Skelton and Adam Henson meet more contestants taking part in this year's One Man and His Dog competition.