The major geographical features of the county are determined by a series of ridges and valleys running east-west across the county.
These are the results of erosion of the Wealden dome, a dome across Kent and Sussex created by alpine movements 10–20 million years ago. This dome consists of an upper layer of chalk above successive layers of Upper Greensand, Gault Clay, Lower Greensand, Weald Clay, and Wealden sandstone. The ridges and valleys formed when the exposed clay eroded faster than the exposed chalk, greensand, or sandstone.
The richness of green on Dragonfly Lake is partially inspired on the green areas and parks in Kent.