Hiroshi Senju Museum Karuizawa (軽井沢千住博美術館)

The painter Hiroshi Senju asked Ryue Nishizawa for a bright, open museum of a kind that did not yet exist: a place where people could take in the world of his works in a luminous space, but also gather, unwind and spend time on their own.

The project ran from 2007 to 2011, the year the museum opened. It is run by the public-interest foundation International Cultural College.

The building is a single room that tilts gently to match the terrain already on the site, in the manner of a landscape. Its floor keeps the undulation of the former ground, where the difference in height is about 3.5 metres. Nishizawa wanted visitors to move through it as one walks in a forest, from place to place, resting on furniture set out here and there: an open space that is both a park and a private living room.

The light is tempered by projecting eaves, a silver screen and glass that filters ultraviolet rays, yet the landscape, the greenery and the brightness of Karuizawa still reach the room softly. Four inner courtyards, some large and some small, glazed all around, bring daylight in as well.

The museum has 2,118.26 square metres of floor area on a site of about 10,000 square metres: 1,786.33 square metres of museum space, 201.99 of gallery and 129.94 of offices. Nishizawa's office handled its design and construction supervision. The café and shop building (398.05 square metres) was designed and supervised by the Yasui Hideo Atelier.

The museum shows the paintings of Hiroshi Senju, a Tokyo-born painter (1958) who works in the Japanese-style nihonga tradition; the works gathered here go back to 1978. Senju sees the place as an ideal one in which to follow his work through the years in order.

A bakery café and a shop share a separate building, and the site also has a gallery. Around the museum, a garden of more than 150 kinds of coloured-foliage plants carries on into the building's four glazed courtyards. In winter the yellow and silver-blue conifers stand out, along with dogwoods whose branches turn red, orange or yellow once the leaves have dropped, and the very white trunks of birches.

The museum opens from 9:30 am to 5 pm, with last admission at 4:30 pm. It is closed on Tuesdays (it stays open on a Tuesday that is a public holiday, during Golden Week and from July to September), and every winter from 26 December to the end of February. Entry is free up to junior high school age, and for visitors with disabilities together with one companion each. Groups of 15 or more are asked to book ahead. A tour of the museum takes about half an hour, depending on crowds.

A taxi ride takes roughly ten minutes from Karuizawa station, served by the Hokuriku Shinkansen and the Shinano Railway, and roughly five from Naka-Karuizawa station, on the Shinano Railway.