Taman Nasional Tesso Nilo

Taman Nasional Tesso Nilo is a lowland rainforest national park located in Pelalawan and Indragiri Hulu regencies in Riau Province, Sumatra, Indonesia, with its main access around Ukui in Pelalawan. Established in 2004, it protects one of Sumatra's last remaining lowland rainforests. It is notable for its high plant diversity, including dipterocarp forests, and as critical habitat for the critically endangered Sumatran elephant and Sumatran tiger.

Visitors can expect a dense lowland tropical rainforest environment with flat to gently undulating terrain, intersected by rivers including the Tesso Nilo River. The park is primarily accessed via Ukui and Lubuk Kembang Bunga area. Visitors can explore forest trails with a guide, observe flora including diverse dipterocarp trees, and have opportunities for wildlife observation, particularly Sumatran elephants at the Elephant Flying Squad camp, as well as birds and other forest fauna. Facilities are basic and visits are typically guided.

Declared as a national park by the Ministry of Forestry Decree No. 255/Menhut-II/2004 on 19 July 2004 with an initial area of 38,576 hectares, and expanded through Decree No. 663/Menhut-II/2009 on 15 October 2009 to 83,068 hectares to strengthen protection of lowland rainforest habitat in Riau.