Everybody knows about the Amazon, the world's largest tropical rain forest. However there are several lesser-known temperate rain forests, such as the Hoh Rain Forest on the Olympic Peninsula in Washington State. The Hoh Rain Forest is characterized by extremely high densities of of plants and other vegetation. Per unit area the rain forest is most productive place on earth--the biomass in these forest is 500 tons/acre, while the tropical rain forest supports a biomass of 300 tons/acre. Additionally, there is more diversity of species in the temperate rain forest here than in the tropical forest. The rain forest serves to store a remarkable genetic diversity.