Retaining Walls are primarily used to hold back earth, but also have other functions in construction and their proper construction and maintenance is fundamental. Retaining walls rely primarily on their mass for stability. Built from paving stones (interlocks) which are placed without the use of mortar (dry stacked). The stones rely on a combination of mechanical interlock and mass to prevent overturning and sliding. Sometimes they are used with a combination of horizontal layers of soil reinforcement to increase the effective width and weight of the gravity mass. Forest Contractors can ensure proper design and construction and also maintenance and repair to ensure safety and soundness of the structure.