Iceland is a European island country in the North Atlantic Ocean on the Mid-Atlantic Ridge. It has a population of about 320,000 and a total area of 103,000 km2 (39,769 sq mi). The capital and largest city is Reykjavík, with the surrounding areas in the southwestern region of the country being home to some two-thirds of the national 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.