Maliau Basin Conservation Area (MBCA) is a remote, pristine wilderness located in south central Sabah. Also known as Sabah's Lost World. Formerly part of Yayasan Sabah Concession Area and covering 39,000 hectares, the area was upgraded to be class 1 Protection Forest Reserve in 1997 and extended to 58,840 hectares, encompassing additional forested areas to the north and the east of the Basin. Maliau received further protection in 1999 when it was gazetted as a cultural heritage site under the state Cultural Heritage (Conservation) Enactment. Buffer zones surrounding the whole Conservation Area also add to its protection.

MBCA is managed by Yayasan Sabah on behalf of the Maliau Basin Management Committee, which also includes Sabah Forestry Department, the Ministry of Tourism Development, Environment, Science and Technology, University Malaysia Sabah and several other agencies.

Over 20 staff members are based in MBCA, monitoring the area and carrying anti-poaching patrols. A new facility, the Maliau Basin Studies Centre (MBSC), will be established at the southeast edge of the Basin for research, education and nature tourism purposes, along simila lines to Danum Valley Field Centre, adjacent to Danum Valley Conservation Area near Lahad Datu.