A botanical garden in Cornwall established in 2001 which attracts 1M visitors per year. The site was a disused clay pit and over 80,000 tonnes of soil were imported in constructing the gardens. The gardens are in three parts, two of them in huge hemispherical greenhouses. The larger is the largest in the world (occupying 1.6ha) and contains a tropical rainforest collection, while the smaller (0.7ha) is for Mediterranean plants. The third part, for temperate plants, is outdoors.