Natural stone work used on both retaining walls and pillars serves functional and decorative roles in your outdoor living area. For example, if you have a steep slope in your backyard, a retaining wall helps to stop yard flooding and erosion. Moreover, your retaining wall adds visual interest as well. It defines a backyard room and creates curves and lines in your overall design. You have a wide range of material choices to bring your outdoor walls together. Pillars add a touch of class as well as serving a functional purpose, just like retaining walls.