The spectacular Sungai Endau is actually one large river fed by several smaller rivers like the Sungai Jasin, Sungai Marong, Sungai Kinchin and the Sungai Kemapan. The river itself traverses the pristine Endau Rompin Forest Reserve, one of the few expansive stretches of virgin lowland rainforest in Peninsular Malaysia.

The hills of Endau are made up largely of ignimbrite, overlain in places with shale, sandstone and clay. This mixture lends itself to some very interesting features like cliffs, waterfalls, rapids and boulder-pools carved out from solid rock by water action. This latter feature is most distinct at Upeh Guling on Sungai Jasin, where many boulder-pools can be found. Bands of granite from steps or sheer cliffs, including the spectacular Buaya Sangkut Falls, discovered in 1985 by the Malayan Nature Society Malaysian Heritage and Scientific Expedition. Both these waterfalls can be reached after a day of trekking.

The Sungai Endau catchments area covers over 420sq km of forested lands. Botanists and scientists researching the area founds the water there of excellent, pure quality. Several plants were discovered that are found nowhere else in the world. Animals in the vicinity of the Sungai Endau include the rhinoceros, elephant, tiger, fox, mouse deer, tapir, bearded pig, wild boar and monkey. Altogether, well over 60 species of mammals have been recorded in the area – an amazing variety that shows the richness of the environment here. Endau Rivers and its surrounding forests are also the habitat to a fascinating variety of rare and exotic tropical birds.

The entire length of the river has scattered settlements of Orang Asli who use the river for their daily needs. As the Sungai Endau nears the sea, it nurtures a unique mangrove swamp ecosystem. Endau town is situated at the river mouth where the river flows into the South China Sea.