Japan is a stratovolcanic archipelago of 6,852 islands. The four largest islands are Honshu, Hokkaido, Kyushu, and Shikoku, which together comprise about ninety-seven percent of Japan's land area. Japan has the world's tenth-largest population, with over 126 million people. Honshū's Greater Tokyo Area, which includes the de facto capital of Tokyo and several surrounding prefectures, is the largest metropolitan area in the world, with over 30 million residents.