Historical Features are physical or cultural features that are no longer visible on the landscape. Examples: a dried up lake, a destroyed building, a hill leveled by mining. The term makes no reference to the age, use, or any other aspect of the feature. A ghost town, for example, is not a historical feature if it is still visible.
Cliff - Very steep or vertical slope on one side (bluff, crag, escarpment, head, headland, nose, palisades,
precipice, promontory, rim, rimrock, scarp).