and South Korea as they regard Okinotorishima as uninhabitable rocks which have no EEZ. The Iwo chain and the outlying islands have no permanent population, but hosts Japan Self-Defense Forces personnel. Local populations are only found on Chichi-Jima and Haha-Jima. The islands form both Ogasawara Subprefecture and the village of Ogasawara, Tokyo. Municipal mergers When Tokyo reached its current extent except for smaller border changes in 1893, it consisted of over 170 municipalities, 1 (by definition: district-independent) city, nine districts with their towns and villages, plus the island communities that had never part of ritsuryō districts. By 1953, the number of municipalities had dropped to 97. The current total of 62 was reached in 2001. National parks As of March 31, 2008, 36% of the total land area of the prefecture was designated as Natural Parks (second only to Shiga Prefecture), namely the Chichibu Tama Kai, Fuji-Hakone-Izu, and Ogasawara National Parks (the last a UNESCO World Heritage Site); Meiji no Mori Takao Quasi-National Park; and Akikawa Kyūryō, Hamura Kusabana Kyūryō, Sayama, Takao Jinba, Takiyama, and Tama Kyūryō Prefectural Natural Parks. A number of museums are located in Ueno Park: Tokyo National Museum, National Museum of Nature and Science, Shitamachi Museum and National Museum for Western Art, among others. There are also artworks and statues at several places in the park. There is also a zoo in the park, and the park is a popular destination to view cherry blossoms. Earthquakes Minor quakes Tokyo is near the boundary of three plates, making it an extremely active region for smaller quakes and slippage which frequently affect the urban area with swaying as if in a boat, although epicenters within mainland Tokyo (excluding Tokyo's –long island jurisdiction) are quite rare. It is not uncommon in the metro area to have hundreds of these minor quakes (magnitudes 4–6) that can be felt in a single year, something local residents merely brush off but can be a source of anxiety not only for foreign visitors but for Japanese from elsewhere as well. They rarely cause much damage (sometimes a few injuries) as they are either too small or far away as quakes tend to dance around the region. Particularly active are offshore regions and to a lesser extent Chiba and Ibaraki. Infrequent powerful quakes Tokyo has been hit by powerful megathrust earthquakes in 1703, 1782, 1812, 1855, 1923, and much more indirectly (with some liquefaction