The Riversleigh World Heritage Area is located in the southeastern section of the Boodjamulla (Lawn Hill) National Park. The World Heritage Area was inscribed for its outstanding natural universal values. It is one of the most significant fossil deposits in the world and the richest known fossil mammal deposit in Australia. It has revealed records of Gondwanan life forms that existed before the separation of this ancient continent. 

Riversleigh D Site was one of the first major fossil deposits found at Riversleigh and is the only publicly accessible part of this World Heritage Area. Its fossils are from the late Oligocene period, dating back 25 million years. Turtles, fish, snails, crocodiles, lizards, pythons, birds and many types of mammal fossils have all been recovered from Riversleigh D Site.