Before bananas, papayas, and other fruits reach supermarket shelves, they have a long ship or air journey behind them - at the expense of the environment. The Klein Eden Tropical House at the Rennsteig shows how tropical fruits can be produced in a sustainable way. The 3,500 square metre greenhouse facility is heated in an environmentally friendly way with the help of waste heat from the neighbouring glass industrial plant. The tropical house is a best-practice example for other energy-intensive operations as well as a research and learning station for science and the public. It is supported jointly by the district, local authorities, companies, and other players in the region.