Sakauchi-mura showcase.

Deep in the heart of the mountainous Gifu Prefecture in central Japan (west of Tokyo and east of Osaka) is a little settlement which straggles along a fiercely rushing river that has formed a steep-sided valley; the sides are covered with that natural dark green tapestry of bamboo, conifer, and deciduous trees that makes the texture of the Japanese countryside so magical and unforgettable.

Sakauchi-mura claims to be the least densely populated village in the country, and it is one that has apparently been little changed for centuries. But of course it has been altered by the economic success of modern Japan, and in some ways it offers its prosperous inhabitants what many people would consider to be an ideal life: plugged into all the networks and fully optically cabled up, but still in close touch with almost unaltered nature and traditional forms of husbandry.

The village's 750 inhabitants naturally preserve their own traditions and ceremonies, but more and more they have to cater for tourists who come to experience the beauties of the village, the valley and echoes of a mythical way of life. So the village asked Makoto Sei Watanabe to make an interpretation centre that would also act as a village hall where small concerts, festivals and community meetings could be held. The architect had never worked in such a place before but was concerned 'to draw out the beauty of nature by adding small artificial objects'.

The major artificial object is really quite large: a 6 metre wide platform cantilevers from the steep bank and out towards the rushing water. The steel structure is elegant but muscular: a tougher object than many would dare to set in such a delicate place. But it is approached from the south along a very gentle ramp which gradually delivers visitors to the end of the platform, where they have an almost panoramic view of the valley. On the way to the brink, the path leads past the chain of spaces which offer tourists information, coffee and maitake gohon (rice with maitake mushrooms, a local speciality). The form of the building is derived from the need to minimise its intrusion into the panoramic view from the end of the deck and to present a more or less blank face to the road. Angled roofs protect platform and the enclosed spaces from sun, rain and snow (this is a wet area of Japan). Like the silver metal-clad walls, the roofs are designed not to obtrude on the panorama, but they have a further function, for as the sun moves round the building their angles cast complex shadows, emphasising the passage of time.

The main space with a glass wall overlooking the valley doubles as the community hall, which, with the platform and the surrounding landscape offers another means of understanding the place. On the less steep part of the river-bank to the west of the main thrust of the platform is an earth sculpture in which Watanabe has created a turfed, wave-like form called 'Edge of Water'. This is not just an abstraction of the landscape forms of the valley fleer but a sitting area when there is a concert on the platform and a stage for performances that can be viewed from the deck.

Running across the grass waves is 'Touched by Wind', Watanabe's third intervention into the landscape: 150 thin carbon-fibre four-metre high poles set on a metre-square grid. Because it is strong and very flexible, carbon fibre is used to make fishing rods and the poles at Sakauchi-mura wave with each caress of wind like a giant field of grain. Each rod is tipped with a luminous diode powered by solar cells that charge during the day, so that the sinuous, trembling movements can be perceived in the dark. 'Touched by Wind' adds another dimension to our understanding of the valley and its village.