Awaji Green Kan (あわじグリーン館)

The Awaji Yumebutai occupies a former earth-quarrying site, from which the material for artificial islands in Osaka Bay, including that of Kansai International Airport, had been taken. The project, run by Hyōgo Prefecture, wanted to restore to the site a nature where plants, animals and humans live together; Ando signed the master plan of its facilities, spread over a park of 130 hectares. The complex opened in March 2000, together with the flower exposition Japan Flora 2000.

The greenhouse opened on 18 March 2000 as 奇跡の星の植物館 (the Miracle Planet Museum of Plants), a facility of Hyōgo Prefecture. Its theme, "creating emotion", made it a new kind of exhibition space, blending art with flowers and greenery. On 18 September 2021, for the flower fair marking the 20th anniversary of the Awaji exposition, it received new installations, including the "Garden Castle", and its present name, Awaji Green Kan.

The building is by Ando, author of the Yumebutai master plan; the exhibition plan, the landscaping and the plantings have another author. The greenhouse offers 6,700 m² of floor area under a great volume about 20 m high, whose ceiling height heightens the sense of scale.

The interior is divided into two zones, "culture of coexistence" (共生文化ゾーン) and "daily life with flowers and greenery" (花と緑の暮らしゾーン). Five exhibition rooms each follow a theme: "green sculpture" (みどりのちょうこく) for succulents of arid regions, cacti and euphorbias; "garden of colour" (しきさいのにわ) for tropical and subtropical plants; "greenery in daily life" (くらしのみどり) for plants of everyday life; "garden of evolution" (しんかのにわ), where the "Jurassic tree" (Wollemia nobilis) grows, discovered in Australia in the 1990s when it was thought to survive only as fossils; and the "lively garden" (にぎわいのにわ), whose symbol is the "Garden Castle", made of growing plants, with devices to make children feel close to plants.

There are also a garden of shade (ひかげのにわ) for plants that grow in low light, a terrace planted with a Pandanus utilis, originating from Madagascar, and tropical fruit trees, an atrium with flowing water, planted with trees from Okinawa, Yunnan, Taiwan and Vietnam, and a special exhibition room devoted to rare plants of Yunnan, in China, and to those that influenced world flower culture.

More than 600 species of rare plants are shown here, alongside works of art.

The greenhouse is open from 10 a.m. to 6 p.m. (last entry 5:30 p.m.). It is normally closed on the Thursday of the second week of each month, with some months changed and exceptional closures; the site's annual calendar gives them. Admission is free up to high school.

The greenhouse is the only paid part of the Awaji Yumebutai: the rest of the park can be visited freely.