In the broad sense Shinjuku is one of the twenty three wards of Tokyo. However, the name also refers to one of the Tokyo urban centers, located around the state railway station and the three access stations. The first station was built here at the end of the 19th century and it became an important communication hub almost immediately. Due to the development of railway Shinjuku grew rapidly and became one of the most vibrant parts of the city. The growth process took only one century. Today Shinjuku Station is a large complex that is the world's busiest transport hub. There are also four of the ten highest Tokyo buildings in the neighborhood.