Belgard. The company’s permeable pavers are made of concrete and separated by joints filled with small stones. Water enters the joints between the pavers and filters through crushed stone layers; the water, minus the filtered-out pollutants, is absorbed into the soil. The pavers can be used for patios, driveways, walkways, pools, and other areas. The manufacturer says its pavers, including Subterra stone (pictured), allow for modular and random installation to create random patterns that look like natural cobblestones. The product comes in multiple shapes, colors, and patterns. 800.899.8455.