Consist of a massive outcrop of greyish - blue limestone, with a vertical face about 300 feet in height, which has been caused by the undermining and solvent action of the water of Crown Swamp Creek along a joint plane. The water disappears at this point, and is not seen above ground for about 3 miles, where it trickles over bars of travertine." Ref: Carne, Joseph Edmund. Mineral Resources of the Western Coalfield,1908, p. 245. The limestone outcrop supports a unique and distinctive vegetation, that includes the White Box Eucalypt, the Grass Tree, Xanthorrhoea glauca and the easternmost example of desert Spinifex Grass, Triodia. It also supports an extensive and unique native land snail fauna.