Countryfile is on the Isle of Man. Adam Henson finds out about the much-forgotten naturalist Edward Forbes, whose contributions to marine biology and oceanography fed into Darwin's theories. Adam explores all creatures great and small on the island, following in Forbes's footsteps and investigating the local rock pools with a group of young marine enthusiasts. He finds out about farming on the island, from the school that has farm-assured status to the native Manx Loaghtan sheep. One animal you wouldn't expect to find living wild on the Isle of Man is the Australian wallaby. Adam goes on a safari to find this unexpected beast. Also including a trip back through the Countryfile archive to look at some of the most fascinating creatures the team have spotted over the years