The Maliau Basin is one of the most spectacular and pristine natural features in Malaysia, and indeed, Southeast Asia. The Maliau Basin is almost unvisited and completely uninhabited by man. It is located in south-central Sabah, about 40km north of the Indonesian border at between 116° 40' - 117° 2' and 4° 40' 4° 50' N.

While all of this region is rugged, remote and forested, the Maliau Basin is distinguished by its steep slope up to 1,500m in height, making it insurmountable on foot from most directions. The size of the enclosed Basin is 390 sq. km with a maximum diameter of 25km. The highest point is Mt. Lotung, on the north rim which is about 1,900m elevation. It is drained by a set of radiating tributaries of the Maliau River, one of which descends a series of waterfalls, known as the Maliau Falls.

The river drains through a gorge into the Kuamut River which in turn feeds into the Kinabatangan River, the longest river in Sabah. The basin is a faunal haven for lowland animals such as wild pigs, barking deer, proboscis monkey, clouded leopard, pythons and many species of birds including the rare Bulwer's Pheasant, the Crimson headed Partridge and the Peregine Falcon have been sighted here.

Since 1970, the area has formed part of a large timber concession assigned to Yayasan Sabah. Since 1981, however, the Maliau Basin and another large area, the Danum Valley, have been designated Conservation Areas within the Foundation's long-term Forest Management Plan, to remain unlogged for purposes of wildlife conservation, education and research.