Answer: keep the stones underneath.
Depending on the cachet of the stones, it may be more advisable to keep them by applying a varnish type glazer beforehand. To receive the tiling, the wall must be lined with water-repellent panels or even plasterboard panels. These choices, well thought out upstream, allow you to ensure a lasting structure. It is possible to tile directly on the stone if the surface is flat. If it is a water feature, a special seal must be provided because the stone under the tiles could soak up water and cause humidity problems. It should be noted that stone tiling is one of the least restrictive forms of renovation in terms of wall covering. You too, send us your brico question