Anita Rani and Sean Fletcher explore the beautiful south west corner of Wales as they celebrate the 70th anniversary of the Pembrokeshire Coast National Park. Anita faces her fears as she abseils 100 feet down a sea cliff to discover how best to protect the nesting spots of the thousands of sea birds that flock here. Sean meets the artist behind the coveted annual fish licence and heads to Angel Bay to discover how to farm oysters. Adam's Exmoor ponies are in for a treat when a farrier gives them a pedicure and they meet a new stallion. and in a special investigation, BBC News's rural affairs correspondent Claire Marshall meets the farmers with Parkinson's Disease who fear their condition could be linked to years of using a toxic herbicide.