On a route from Pwll to Kidwelly, Derek Brockway turns Pied Piper as he launches a walk of 800 children marking the anniversary of 'People Power' that saved a stretch of the Loughor Estuary for families to enjoy. On this Carmarthenshire coastal walk, the weatherman also discovers a former munitions factory that employed 6,000 people, has a spin in a racing car and learns the story Wales' feisty warrior princess Gwenllian