Shinjuku

, officially called Shinjuku City, is a special ward in the Tokyo Metropolis in Japan. It is a major commercial and administrative center, housing the northern half of the busiest railway station in the world (Shinjuku Station) and the Tokyo Metropolitan Government Building, the administration center for the government of Tokyo. , the ward has an estimated population of 346,235 and a population density of 18,232 people per km2. The total area is 18.23 km2. Since the end of World War II, Shinjuku has been a major secondary center of Tokyo (fukutoshin), rivaling the original city center in Marunouchi and Ginza. Shinjuku is also commonly used to refer to the entire area surrounding Shinjuku Station. The southern half of this area and the station in fact belong to the Yoyogi and Sendagaya districts of the neighboring Shibuya ward. History In 1634, during the Edo period, as the outer moat of the Edo Castle was built, a number of temples and shrines moved to the Yotsuya area on the western edge of Shinjuku. In 1698, Naitō-Shinjuku had developed as a new (shin) station (shuku or juku) on the Kōshū Kaidō, one of the major highways of that era. Naitō was the family name of a daimyō whose mansion stood in the area; his land is now a public park, the Shinjuku Gyoen. In 1898, the Yodobashi Water Purification Plant, the city's first modern water treatment facility, was built in the area that is now between the park and the train station.