Conventional or gravity segmental retaining walls (SRWs), referring to manufactured retaining walls, as opposed to natural stone walls, effectively limit the movement of the soil behind them, primarily by the weight of their blocks. The maximum wall height of a single-depth wall is typically directly proportional to its weight, width, batter (face slope), soil condition, and site geometry. (Contractors should, in all cases, refer to the manufacturer’s instructions for specific recommendations.) The theory behind these retaining walls is to effectively alter the landscape to increase the area of usable land. On occasion they may be used in cases where there is a very steep or rapid change in the site grading. Retaining walls actually have an extensive history dating back to the introduction of primitive agriculture. These early efforts to improve agricultural production often used readily available local materials to alter the existing natural terrain and drainage patterns.