Iceland ⁱ/ˈaɪslənd/ (Icelandic: Ísland, IPA: [ˈislant]; see Names for Iceland), described as the Republic of Iceland, is a Nordic European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains about 98.6% of the population and comprises more than 99.9% of the land area. The country has a population of about 320,000 and a total area of 103,000 km² (40,000 sq mi). The capital and the largest city is Reykjavík, with the surrounding areas in the southwestern region of the country being home to two-thirds of the country's population. Iceland is volcanically and geologically active. The interior mainly consists of a plateau characterised by sand fields, mountains and glaciers, while many glacial rivers flow to the sea through the lowlands. Iceland is warmed by the Gulf Stream and has a temperate climate despite a high latitude just outside the Arctic Circle.