Tropical rainforests are located along the equator where temperatures and humidity are high. They receive between 4-8 meters of rain per year. The largest rainforests are found in Central and South America, Southeast Asia, and West Africa. Tropical rainforests are at risk of destruction due to human activity, with over half of the original forests already destroyed. The biodiversity of these forests is high, containing many species of plants and animals, some of which may provide cures for human diseases.