Ski run provided with a means for preserving snow on the skiing surface, said means comprising at least pipes suitable for the flow of a cooling agent for cooling the snow present on the skiing surface, said pipes (1) being embedded and located in a layer (5) enabling, when the layer (5) has a temperature of at least 2.degree. C., a water percolation through the layer (5). Below the layer (5), a draining system (6,7) is placed for collecting and draining at least substantially all the water percolating through the layer (5) in which the pipes (1) are embedded.