Some caves are so fragile and still so important for mankind, that it is important to save it and still make it accessible to the public. Since the sixties, museums and institutions all around the world develop techniques to copy caves as perfect as possible.
Early attempts were not really realistic. Speleothems removed from a cave were placed in a sort of labyrinth to produce a sort of artifical cavern. Unfortunately this had two drawbacks: the cave was destroyed and the result was not really satisfactory. A famous negative exaple was the so-called model cave of Keith and Allabaugh, who cleared out parts of Bethlehem Cave, SD, usa.
The first success in building artificial caves was made by the Deutsches Museum, Munich, Germany. In the sixties they made the most elaborated replica of Altamira, which was possible at this time. They modelled the ceiling of the cave and painted the surface the same way as the original cave was painted.
The newest technology is based on modern three-dimensional sensors. A laserscanner makes 2.5-dimensional digital models of the caves walls and ceiling, multiple images combined produce a nearly complete three-dimensional model of the surface. Then the surface is photographed completely and the twodimensional images are then projected onto the digital model. The result is a digital model of the cave. This model can be displayed on regular computers, in virtual rooms (like CAVE) and with VR helmets. And of course it can be used to produce solid models of the cave in any desired size.
This new technology was used to make a model of Grotte Cosquer at the French coast near Marseilles and Karnak in Egypt.