This swimming pool in Switzerland with a movable stone floor is a true item of clock-making precision, not only because of its oval shape, but also because of its peripheral overflow. The result was so successful that it is hard not to play with the control panel and to keep changing the décor and the surroundings: blending it in with the lake, turning it into a mirror, and making it disappear and reappear to create a crystalline wave all of which suddenly give the impression of controlling nature.