The 2,909-hectare site near the town of Soufrière includes the Pitons, two volcanic spires that rise side by side from the sea (770 and 743 meters high, respectively) and are connected by the Pitonmitan Ridge. The volcanic complex includes a geothermal field with sulfur fumaroles and hot springs. Coral reefs cover nearly 60% of the marine area of the site. A survey found 168 species of fin fish, 60 species of cnidarians (including corals), 8 species of molluscs, 14 species of sponges, 11 species of echinoderms, 15 species of arthropods, and 8 species of annelid worms. The predominant terrestrial vegetation is tropical moist forest, transitioning gradually to subtropical moist forest, with small patches of dry forest and moist coppice on the mountaintops. At least 148 plant species are found on the Great Pitons and at least 97 species on the Little Pitons and its intervening ridge, including 8 rare tree species. The Greater Pitons are home to approximately 27 bird species (five of which are endemic), three native rodent species, one opossum species, three bat species, eight reptile species and three amphibian species.