What the Old Library and Storehouse is
The National Astronomical Observatory Old Library and Storehouse, built in 1930 in the middle of the Mitaka campus in Osawa, Mitaka City, Tokyo, is a two-storey reinforced concrete building of 100 square metres with a sheet-metal roof, registered as a Registered Tangible Cultural Property in 2014.
It was built to hold paper. Books and records were kept here until the end of the twentieth century; after a separate reading room opened in 1972 it served as the stack, and once the present library was completed in 2000 it became a store.
A rendered addition was built on the west side in 1961. The Agency for Cultural Affairs notes that the extension had been anticipated from the start, and the observatory describes that western part as three storeys.
Why it is registered
The criterion here is different from the rest: the National Astronomical Observatory Old Library and Storehouse was listed as a model of design, register number 13-0334, and it is the only one of the ten Mitaka entries in that category.
The other nine were registered either as difficult to reproduce or as contributing to the historic landscape. This building is neither an instrument housing nor part of the entrance composition. It was judged on how well it was designed as a piece of early Showa architecture.
The exterior carries no ornament to speak of, which puts the weight on other decisions: how the windows are spaced, how the canopies are carried, how the tile is laid.
What to look at
The walls are finished in Scratch tile, the same material used on the solar tower nearby and a favourite of Japanese public architecture around 1930.
Slim canopies run horizontally above and below the windows, carrying an unbroken line across the facade. On a small two-storey block, that line does a lot of work in settling the proportions.
Do not miss the round window on the ground floor. Among rectangular openings it sits like a deliberate intruder.
The 1961 addition on the west is finished differently, so the join is easy to read. You can trace with your eye exactly how much of the National Astronomical Observatory Old Library and Storehouse dates from 1930.
Visiting
The National Astronomical Observatory Old Library and Storehouse is exterior only. It remains in use as a store and the interior is closed. An audio guide is available.
The visitor route passes on the east side, which is the best face for the run of canopies and the round window; stand back far enough to take the whole wall in at once.
Photography is allowed for private use. Opening hours, reception and bus access are common to the site and are set out on the page for the National Astronomical Observatory of Japan Mitaka Campus.
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Q&A
- What was the National Astronomical Observatory Old Library and Storehouse used for?
- It held the observatory's books and records until the end of the twentieth century, served as the stack after a separate reading room opened in 1972, and has been a store since 2000.
- Can I go inside the National Astronomical Observatory Old Library and Storehouse?
- No. The interior is closed and the building is seen from the outside.
- When was the National Astronomical Observatory Old Library and Storehouse built?
- In 1930, with a western addition in 1961. It was registered in 2014.
- Why was the National Astronomical Observatory Old Library and Storehouse registered?
- As a model of design. It is the only one of the ten Mitaka entries listed under that criterion rather than for irreproducibility or landscape value.
- What should I look for at the National Astronomical Observatory Old Library and Storehouse?
- Scratch-tile walls, the continuous slim canopies above and below the windows, the round ground-floor window, and the visible join with the 1961 addition.
Basic Information
| Name | National Astronomical Observatory Old Library and Storehouse |
|---|---|
| Location | 2-1007-1 Osawa, Mitaka City, Tokyo |
| Designation | Registered Tangible Cultural Property (building) |
| Year Designated | Registered in 2014 (Heisei 26) |
| Quantity | 1 building |
| Dimensions | Reinforced concrete, 2 storeys, sheet-metal roof, floor area 100 square metres |
| Owner | Inter-University Research Institute Corporation National Institutes of Natural Sciences |
| Public Access | Exterior only; interior closed |
References
- Agency for Cultural Affairs, National Cultural Properties Database: National Astronomical Observatory Old Library and Storehouse
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00009919
- National Astronomical Observatory of Japan: Old Library
- https://www.nao.ac.jp/about-naoj/organization/facilities/mitaka/visit-facilities/old-library.html
- National Astronomical Observatory of Japan, Mitaka Campus: Visitor Information
- https://www.nao.ac.jp/about-naoj/organization/facilities/mitaka/visit.html
Last verified: 2026.09.13
