Tepuis are flat-topped mountains found primarily in the Guiana Highlands of South America, particularly in Venezuela, Guyana, and Brazil. They are characterized by steep cliffs and a unique ecosystem, often referred to as "islands in the sky." Tepuis are composed of ancient sandstone and can reach heights of over 3,000 meters. These formations are home to many endemic species of plants and animals, meaning they are not found anywhere else in the world. The isolation of tepuis has led to the development of unique habitats, making them important sites for biological research and conservation efforts.