Retaining walls are a fantastic solution to reduce erosion, more defined garden bed edging, to level landscape areas, improved water drainage, for structural support as well as other things. It's important to know your local council guidelines when building a retaining wall while invovling a professinoal such as a structural engineer, landscaper, or retaining wall builder where appropriate. There are a variety of different materials you can choose from as well as other things to consider when deciding to build a retaining wall.