Retaining structures are engineering solutions designed to hold back soil and prevent erosion or landslides. They are commonly used in areas with steep slopes or where excavation has occurred. These structures can be made from various materials, including concrete, stone, or timber, and are essential for maintaining the stability of landscapes and infrastructure. There are several types of retaining structures, such as gravity walls, cantilever walls, and sheet piles. Each type serves a specific purpose based on the soil conditions and the height of the wall needed. Proper design and construction are crucial to ensure their effectiveness and safety.