The topography of the bigger islands - particularly Luzon and Mindanao - is characterized by alluvial plains, narrow valleys, rolling hills and high mountains. The highest mountains are found in Mindanao and Luzon, with the altitudes varying from 1,790 to 3,144 meters. Most of the smaller islands are mountainous in the interior, surrounded by narrow strips of discontinuous flat lowlands which constitute the coastal rims. The shorelines of both large and small islands are irregular.
The Philippines' fertile land accounts for the more than 900 species of orchids representing 100 genera that have been found. The sampaguita is the national flower.
Among the country's fauna are some endangered species like the Philippine Eagle, the tarsier, and the mouse deer.