The Cliff Brush works somewhat similarly to the Lower To brush. When the tool is selected, you will be prompted for a height. This determines the height that will be the bottom of the cliff. Move the selector to the area where you want to make a cliff. The two discs show where the top and bottom of the cliff will be created. When the left mouse button is clicked the area highlighted by the circle will be “scraped away” and flattened at the base of the cliff.