Eden Project biomes. Visitors in the interior of the humid tropics biome (dome) at the Eden Project. The Eden Project is situated in Cornwall, England in a disused quarry. It is a botanical and horticultural garden that is centred on two large greenhouse biomes, which together form the largest greenhouse in the world. The biomes are geodesic domes holding windows of ETFE plastic (ethyltetra- fluoroethylene). The Eden Project displays the diversity of plant life across the world that has a relationship with humans. These include cola, spices, cork, tobacco and fruits & vegetables.