In the past, people living in northeast China would go to the public bath because there were no showering facilities in most families. The winter of the northeast is cold and long, so people would usually stay in the warm public bath very long. It gradually became the most relaxing and favorite social place for people. Nowadays, “gym” has almost taken the place of “public bath”, and has become people, especially young people’s popular social and recreational place: it has water, people can swim and shower, and it is healthier and more fashionable. Therefore, “water” is not simply a symbol of the collective memory of Northeast China. It is the medium that can connect and heal. Since the swimming pools and other areas need dry and wet separation, how to properly design the “boundary” naturally becomes the key of design. We attempted to introduce multiple geometrical systems into the homogeneous frame structure to create flexible, continuous, and changing “boundary”, which allows spatial and visual connection between “water” and other functional areas, and simulation of events across the boundary. On the first floor, we used lines and curves to form the continuous dry and wet separation, which naturally becomes the boundary between the swimming area and the play area, with two independent circulations. The continuous in and out curve allows the two spaces to invade each other, creating interesting moments: people in two areas could see each other and thus get connected. On the third floor, we located the standard pool on the south side double-height space. The elevation of the steel-structure pool’s surface is actually on the three and half floor, so it leaves a half-floor-height space below the swimming pool aisle. The diagonal structure members of steel-structure swimming pool are covered by negative semicircle finished panels, forming the quiet and comfortable small-scale rest spaces. The gap between the aisle along swimming pool and the floor plate of fourth floor is filled with frosted glass blocks, allowing the natural light of double-height swimming area to permeate evenly into the rest area. We made acrylic openings between every two diagonal structure members along the sidewall of swimming pool, turning the introversive space, the space to be seen to an extroversive space, the space to see. On the fourth floor, the dry and wet separation between the gym area and the double-height swimming pool space is formed by glass partitions, allowing people in gym to watch the pool from any angle. For the boundary between VIP training and general training, we designed a winding steel-frame partition, with glass and mirror alternatively installed in, allowing permeation from the two spaces.