Edo Castle located in Chiyoda, Chiyoda-ku, Tokyo is the residence of the Imperial family of Japan. It was constructed in 1457 by Ota Dokan. Since 1590, when Tokugawa Ieyasu moved to this castle, works of expansion, improvement and maintenance had been performed. All the works were completed in 1636 during the reign of the third Shogun, Iemitsu. The castle had been resided by 16 generations of the Shogun and had functioned as the center of the Tokugawa Shogunate in the Edo period (1603-1868). At the Meiji Restoration in 1868, the castle was bloodlessly surrendered to the Meiji government. In the next year, the capital of Japan was transferred to Tokyo and the castle became the Imperial Castle. In 1948, the west part of the site was renamed to Kokyo (imperial Palace) and the Honmaru (the main castle) and Ninomaru (the second castle) were open to public during the daytime as Higashi-Gyoen (East Garden). The Gaien (outer garden) area and Kitanomaru (the north castle) area are open to public for 24 hours as a public park. This castle is one of the world’s largest castles in a total area of the castle compounds. It has been the symbol of Japan from the Edo period up to the present time.