Only the hardiest of beasts survive in Britain's mountains and uplands, including the golden eagle and its prey the mountain hare, plus 400,000 red deer and flamboyant black grouse.
Britain's forests contain majestic trees, some of them thousands of years old. Behind the leafy veil, there are booming populations of previously rare wild boar and goshawks.
From sandy beaches to soaring cliffs, Britain's coastlines are one of nature's wildest habitats, where hardy creatures are battling to survive.
A look at some of Britain's wildest and wettest corners, and their inhabitants. Beavers display their skills as landscapers, a water spider constructs its own air tank, and starlings put on a head-turning display to keep a peregrine falcon at bay.
In the varied water worlds all kinds of wildlife thrive, from slithering grass snakes to delicate reed warblers.
Evidence of how the countryside has changed more in the last 100 years than in the previous two thousand. Barn owls fight for their territory against kestrels.
On North Ronaldsay, one rare breed of sheep can subsist on a diet of only seaweed. In the Shetlands, otters benefit from a current of warm water flowing up from Spain.
Hedgehogs have declined in numbers from 30 million to one million in 60 years. Great crested newts enjoy an elaborate courtship in larger ponds.
