Walls and terraces can be beautiful, function or both! Decorative and planter walls can add dimension to a yard. Retaining walls can create more usable space or make existing spaces safer from erosion and flooding. Pilasters make wonderful decorative additions to both front and rear yards. A variety of materials can be utilized: stackable block, concrete block faced with stucco or stone, or even decorative masonry block like slump stone or split face.