Japan is an archipelago consisting of over 6,800 islands. The three largest islands are Honshu, Kyushu and Shikoku, together accounting for almost ninety-seven percent of Japan's land area. Most of the islands are mountainous, many volcanic; Japan’s highest peak, Mount Fuji, is a volcano. Archaeological research indicates that people lived in Japan as early as the Upper Paleolithic period. The first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other nations followed by long periods of isolation has characterized Japan's history.