The best open-air bath, facing the cold snow world outside, in the cold day with the temperature close to -15 degrees Celsius, the sky is the dome, the mountain is the screen, the lake is the painting, and the majestic pines and branches are the embellishment. In the beautiful "bathroom" of nature, we are like those visiting swans, swimming freely, breathing the cool and pure air, feeling the gentle caress of the spring water, immersed in the white and dreamy scenery, and our bodies become transparent and light.