The jungles of Sabah host a diverse array of plant and animal species. Most of Sabah's biodiversity is located in the forest reserve areas, which formed half of its total landmass of 7.34 million hectares. Its forest reserve are part of the 20 million hectares equatorial rainforests demarcated under the Heart of Borneo initiative. The forests surrounding the river valley of Kinabatangan River is the largest forest-covered floodplain in Malaysia. The Crocker Range National Park is the largest national park in the state, covering an area of 139,919 hectares. Most of the park area are covered in dense forest and important as a water catchment area with its headwater connecting to five major rivers in the west coast area. Kinabalu National Park was inscribed as a World Heritage Site by UNESCO in 2000 for its richness in plant diversity combined with its unique geological, topographical, and climatic conditions. The park hosts more than 4,500 species of flora and fauna, including 326 bird and around 100 mammal species along with over 110 land snail species.