Teshima, an area distinguished by its splendid landscape, had been misused since the mid-1970s as an illegal dump for toxic waste. With the turn of the millennium, however, came a structural transformation of the region. The basis for this was a revival of traditional agriculture and a desire to make this remote area a cultural attraction. In this respect, the art museum plays a central role. A close collaboration between the architect and the sponsor, Soichiro Fukutake, together with the artist Rei Naito, led to the creation of the present white concrete shell with its free curves. This low-height structure fits perfectly into the hilly landscape. Two oval openings link the interior with the outside world, and the sun creates an interplay of light and shade on the smooth surfaces. Inside, the sole exhibits are drawn from nature. Extensive structural calculations and material analyses were necessary to restrict the arc of the dome to a height of four and a half metres and the thickness of the shell to 25 cm. The form was implemented by precisely recreating the topography of a hill, based on 3,500 points of measurement. A bed of mortar was poured over this, and reinforcement laid on top. The special concrete, with white cement and a lime additive, was poured in a single day, smoothed, and coated with a layer of plastic. After five weeks, the earth was removed from inside and the surface covered with a water-repellent finish.