Tokyo Metropolitan Government Building (東京都庁舎)

Before Shinjuku, the metropolitan government sat in the Marunouchi district of Chiyoda, around where the Tokyo International Forum now stands. Kenzō Tange had designed that earlier city hall in 1952.

An invitation-only competition for the new headquarters was held in 1986: Tange came first and was given the design.

The Shinjuku site was that of the Yodobashi water purification plant, in service until 1965, which supplied water to a wide area of Tokyo. The complex was completed there in 1991, and the metropolitan government began working in it in April of that year.

The complex has three buildings. Building No. 1 rises to 243.40 m with 48 floors above ground and 3 basements; No. 2 is 163.30 m high with 34 floors above ground and 3 basements; the assembly building is 41 m, with 7 floors above ground, 1 basement and 1 rooftop level. The site covers 42,941 m² and the total floor area reaches 380,504 m².

The upper part of Building No. 1 divides into twin towers. Unusually for a skyscraper, its exterior walls are clad in stone.

The design draws on the dense vertical lattices (kumiko) of Edo-period houses, and also evokes a futuristic integrated circuit. The sky corridor between Buildings No. 1 and No. 2, where stone would have been too heavy, is finished with a sprayed coating that imitates stone.

Three bridges link the site to the neighbouring park. From the north they are called the Rainbow Bridge, the Green Bridge and the Water Bridge, after the rainbow seen in the park's waterfall, the colour green, and the water bureau's pumping station.

This is the headquarters of the Tokyo Metropolitan Government; the chamber where the metropolitan assembly holds its plenary sessions is in the assembly building.

Each of the two towers of Building No. 1 carries an observation room at 202 m, on the 45th level. To the north-east one sees the Tokyo Skytree; to the south-east, Shinjuku Gyoen National Garden and the Meiji Shrine; to the south-west, the Shinjuku Park Tower and Tokyo Opera City; to the west, Mount Fuji, visible on many days between December and February. Tokyo Bay can be seen too.

The complex also includes a civic plaza of 3,000 m² that residents may cross and stroll through freely. After sunset, a free video-projection show is staged on the facade of Building No. 1 all year round.

The observation rooms are free and cannot be booked. A dedicated lift runs up to them from the ground floor of Building No. 1.

The south room is open from 9:30 to 22:00 (last entry 21:30) and closes on the first and third Tuesdays of the month. The north room is open from 9:30 to 17:30 (last entry 17:00), and until 22:00 on days when the south room is closed; it closes on the second and fourth Mondays of the month. When a room's closing day falls on a public holiday, it opens that day and closes on the next weekday instead. Both rooms close from 29 to 31 December, on 2 and 3 January and on building inspection days.

The assembly chamber can be visited from 9:00 to 17:00, except on Saturdays, Sundays and public holidays, from 29 December to 3 January and during plenary sessions.

Tochomae Station on the Toei Oedo Line is directly connected to the building; JR Shinjuku Station is about ten minutes' walk away, from its west exit.