Hokkaido is famous for its volcanoes, natural hot springs (onsen), and ski areas, the northernmost of Japan's main islands. The territory of Hokkaido is 83,456.58km2, which is 22 percent of the country's total land area. Hokkaido, as a country, is currently the world's 21st largest island. The people of Japan are proud of the big island, where nature combines so well with the lives of people. Hokkaido is famous for its high quality and freshness of its seafood because the cold waters around the northernmost prefecture of Japan are ideal for fish and sea vegetation. It was formerly known as Yezo, Yeso, Ezo, or Yesso. Some areas in the county are particularly famous for a specific commodity, such as Rishiri and Rebun's uni (sea urchin).