The Rainforest Biome is the larger of Eden's two covered biomes. 100 meters wide, 200 metres long and 55 metres high, with an area of 15,590 square metres, it is the world's biggest greenhouse. The Rainforest Biome contains tropical plants such as banana trees, coffee, rubber and giant bamboo. The other biomes are the smaller Mediterranean Biome and the Outdoor Biome.

The biomes are constructed from a tubular steel frame with transparent panels manufactured from a plastic called EFTE (Ethylene TetrafluoroEthylene). The panels are transparent to UV light and have a triple-membrane structure which provides them with excellent heat insulation properties.

The temperature in the Rainforest Biome ranges from 18 to 35°C, humidity is maintained by a network of misting sprays and a waterfall. The climate is regulated using computerised systems, but relies on the natural properties of the environment such as the rear cliff wall which absorbs heat from the sun during the day and releases it at night. The plants themselves also help control the environment, releasing moisture to cool the air when it gets too warm.