Wrangel Island

It is an island in the Arctic Ocean, between the Chukchi and East Siberian Seas. It is part of Russia and lies across the 180° meridian. It is about 78 miles wide and 2,800 square miles in area. The highest point on the island is Sovetskaya Mountain with 3,596 feet.
This rocky island has a weather station, a single permanent human settlement, and is a breeding ground for polar bears, having the highest density of dens in the world, seals and lemmings. During the summer it is visited by many types of birds.
During the last ice age, the mammoths lived on Wrangel Island and it has been shown that mammoths survived on this island until 1700 BC, which is the most recent survival of all known mammoth populations.
Its flora includes 417 species of plants, double of any other arctic tundra territory of comparable size, and more than any other Arctic island. For these reasons the island was proclaimed the northernmost World Heritage Site in 2004.