Another sort of Zen garden is the rock garden. There appears to be a fair amount of symbolism in rock gardens, too, but I am unaware of exactly what it is, so we can focus on the aesthetic elements. Aesthetically, rock gardens are pure sculpture, so the placement of the rocks is of paramount importance, as is the shape and texture of the rocks themselves. This garden achieves a pleasing arrangement partly by the irregularity, which in this case suggests symmetry without actually having any. It also mimics nature: one could imagine this to be Krakatoa before the volcano exploded, or perhaps some picturesque South Seas island. Note, too, that moss is still the ground cover.