Add Drama to a Retaining Wall Water features don?t have to include plants or fish. The sound of water and the drama of design can be enough for some gardeners and gardens. This water feature -- cleverly used as both retaining wall and focal point -- repeats the classic shapes and materials in the rest of the outdoor space. Best For: Gardeners whose focus is design with water. Pools and fountains along a wall are all about the look and sound.