Countryfile is in Carmarthenshire, where Matt Baker explores the explosive history of the sand dunes. Helen Skelton visits the National Botanic Garden of Wales, discovering how they're mapping the DNA of every flower in the country and how they're preparing their bees for winter.Falklands veteran Simon Weston shows Countryfile around his beloved south Wales and, in the second part of a special series, Adam Henson is in New Zealand to find out how they farm on the other side of the world. What happens when a protected species recovers to the point it impacts rural businesses and other wildlife? Tom Heap reports on a new initiative aimed at saving fisheries from otters.