The seas and islands of the Siberian Arctic are a serious challenge to the navigator, but powerful icebreakers have opened the way to the Northeast Passage, a region which is home for a world-beating range of superb animals. Polar bears and walrus are common, some of the world's rarest birds are everyday sightings, some of the seabirds breed here in uncountable numbers. The islands are largely unexplored and scenically magnificent, a magnet for expedition vessels and adventurous tourists.