The Park consists of steep, almost inaccessible mountainous terrain. A part of the 2.5-million hectare Tropical Rainforest Heritage of Sumatra, which is a World Heritage Site, encompasses smaller nature reserves. Also, the Alas River runs through the Park into an eastern and western half; last place where orangutans, tigers, elephants, rhinoceros and leopards lived together. The park measures 1,092,692 hectares; North Sumatra and Nanggroe Aceh Darussalam (Southeast Aceh, South Aceh, Aceh Singkil) and Regency of Langkat, Indonesia.