The Eden Project is an agricultural education facility located in the Cornwall region of southwest England. It is comprised of a number of domes and open spaces that house plant species from around the world, with each emulating a natural biome. They are constructed out of a hexagonal space frame made up of tubular steel. The cladding is comprised of several layers of thin UV-transparent membrane, which is sealed around their perimeter and inflated to create a large cushion. The structure is completely self-supporting, with no internal supports which is ideal for large uninterrupted spaces filled with plants and trees. The enclosed structures also allow for precise control of the temperature and humidity, so that the Rainforest Biome can be kept at tropical temperature, while the adjacent Mediterranean Biome can be kept warm and arid.