Occasionally, the underlying base of a Gray Natural Cobblestone surface may settle, but it is a relatively easy matter to remove stones, lay additional base material, and reinstall the stones. Heavy traffic driveways tend to encounter this more frequently, however, it can typically be avoided by properly preparing the paving bed. Gray Natural Cobblestone is an extremely versatile building material that can be used in a variety of outdoor applications such as when constructing driveways, walkways, patios, and outdoor dining areas.