At the eastern side of Lake Mungo, millennia of westerly winds have created substantial layered dunes of clay (as dust) and sand. Loss of the covering vegetation, largely as a result of rabbit plagues early in the 20th century, has created erosion and dune mobility: that, in turn, has exposed the remains of long-extinct megafauna and the earliest dated human ritual cremation (at over 40,000 years). The scientific value of the area has resulted in World Heritage listing, but also means there is limited public access to the western side of the dunes, which are known as the "Walls of China". Second image in note. Best on black.