The present invention relates to a prefabricated swimming pool made of metal, especially stainless steel, or of plastic, that is made of one piece or made up of individual segments (1′) and has a water circulation system (8) that, either continuously or at regular intervals, removes parts of the pool water from the swimming pool, runs it through a dirt filter and returns it to the pool, which achieves a flow in the pool water created by the circulation of the pool water. The swimming pool is characterized by the fact that the pool floor (1) is curved, at least in part, along one of its axes, preferably along its lateral axis, with at least 25 percent, preferably at least half, and especially preferably with the entire surface of the pool floor (1) being curved along this axis.