Chimneys(13)Fireplaces(8)Patios, Kitchens, Stairs(7)Retaining Walls(3)Sculpture(1)Stone Restoration(4) Boulder Wall Using salvage stone boulders to create a retaining wall. Roebling Drystack wall located along the Delaware river basin. Massive stones were used, Your Stone Garden walls, retaining walls… if you have stone laying around, that’s half the work.