This series explores five of Britain's most extreme winter landscapes, looking at the conditions that challenge both the wildlife and people that try to survive in the countryside and uncovering a world few get to see.
　　Ellie Harrison looks at British mountains as she reveals the surprises this terrain holds, from volcanoes to avalanches, frogs attempting to spawn to the small herds of reindeer in Britain. There's more than meets the eye to this landscape in winter.