Japan is an island nation in East Asia comprising a large stratovolcanic archipelago extending along the Pacific coast of Asia. The country is north-northeast of China and Taiwan (separated by the East China Sea) and slightly east of Korea (separated by the Sea of Japan). Its primary islands are Hokkaidō, Honshū (the "mainland"), Shikoku and Kyūshū. There are also about 3,000 smaller islands, including Okinawa, some inhabited and others uninhabited. In total, as of 2006, Japan's territory is 377,923.1km², of which 374,834km² is land and 3,091km² water.
About 75% of Japan is mountainous, with a mountain range running through each of the main islands. Japan's highest mountain is Mount Fuji, with an elevation of 3776 m (12,388 ft). As Japan is situated in a volcanic zone along the Pacific deeps, frequent low-intensity earth tremors and occasional volcanic activity are felt throughout the islands. Destructive earthquakes occur several times a century. Hot springs are numerous and have been exploited as an economic capital by the leisure industry. Scattered plains and basins (in which the population is concentrated) cover only about 25% of the nation. The largest, the Kanto Plain, where Tokyo is situated, covers only 13,000 square kilometers. Rivers are generally steep and swift, and few are suitable for navigation except in their lower reaches. Most are fewer than 300 kilometers in length, but their rapid flow from the mountains makes them more than suitable for generating hydroelectric power.
Japan is informally divided into eight regions. Most regions contains several prefectures (the exception being Hokkaidō) for a total of 47. Within these prefectures, there exist many local administrative units that are categorized into designated cities (17), core cities (37), special cities (44), cities, towns and villages depending on the unit's population size.