Greenland is the largest island on Earth, with a heart of ice: 1.7 million square kilometres in size and up to three kilometres thick, Greenland's ice cap is the second largest mass of ice on Earth after the Antarctic ice. It determines the climate, weather and living conditions of the animal world. In the north-east lies the largest national park on earth, its area larger than that of France and Great Britain combined. This is the realm of polar bears, musk oxen and walruses. Hard to spot in the deserted expanses, there are also a few white wolves. Millions of crab divers breed on Greenland's coasts every year - when breeding begins in spring, they sometimes fly in huge flocks, a unique natural spectacle. Filmed in HD for the first time: Polar bear chases off ravens while plundering nests, mass flocks of crab divers.