Lots of boulders of all sizes and shapes. You just can't beat the geology here as it's all the same though it doesn't appear so.

The large granite rocks around Hidden Valley act as giant water collectors. Rainfall runs off through cracks in the rock and collects around the base. The soil itself is composed of weathered granite, and the texture and depth of the soil controls how much water is stored. Plants growing nearer to the rocks will have greater access to moisture and protection from the drying winds.