and exit the Diet building and is called “the door that never opens” because of its restricted access. The entrance is used when Diet members attend their first session after a House of Representatives general election or a House of Councilors regular election and when welcoming the Emperor or foreign heads of state into the Diet building. It is also used to allow visitors into the building during open house events. Central hall The lobby behind the central entrance and right below the central tower is what is called the central hall. The hall has a stairwell that reaches from the second floor to the sixth floor and a ceiling that is high. The ceiling is made of stained glass and has four oil paintings of Japan's four seasons in its corners. The paintings each depict Mount Yoshino in the spring, Lake Towada in the summer, Okunikko in the fall, and the Japan Alps in the winter. They were drawn not by famous artists but by art students. In the four corners of the central hall are statues of Itagaki Taisuke, Okuma Shigenobu, and Ito Hirobumi who were instrumental in establishing constitutional government in Japan, and an empty pedestal. It is not clear why there is an empty pedestal. Some claim original designers could not reach consensus on whose statue to install, or that it encapsulated the idea that politics is never complete. Others say designers left it open to urge politicians today to outstrip the three grand predecessors, or that they avoided erecting a statue with its back to the Imperial palace. The empty pedestal is displayed with a big pine bonsai on the first day of the Diet session. Central tower The central tower measures in height, and surpassed Mitsukoshi’s main store () which was the tallest building at the time the Diet building was constructed. It remained the tallest building in Japan until Hotel New Otani’s main -building was constructed in 1964. Inside the pyramid-shaped dome is a large hall, from the center of which a spiral staircase leads up to the observatory on the top floor of the tower. The observatory is said to have offered a panoramic view over Tokyo, but both the observatory and the hall are closed today to all but the building manager. Even Diet members must obtain permission to enter. The fourth floor of the central tower is a sub-office of