The TRHS includes the highest volcano in Indonesia, Gunung Kerinci (3,805 m asl) along with many other physical features of exceptional natural beauty, including; Lake Gunung Tujuh the highest lake in Southeast Asia, numerous other volcanic and glacial high-altitude lakes, fumaroles, waterfalls, cave systems and steep rocky backdrops. Both Gunung Leuser National Park and Bukit Barisan Selatan National Park contain frontages to the Indian Ocean, making the altitudinal range of the TRHS extend from the highest mountains on Sumatra to sea level. All three protected areas in the TRHS exhibit wide altitudinal zonation of vegetation, from lowland rainforest to montane forest, extending to sub-alpine low forest, scrub and shrub thickets and covering an astounding diversity of ecosystems.