This project is an entry for the international open-idea competition “Borders” organized by Arch Out Loud. The brief challenges designers to explore the possibility to create an underground bath house within the Korean Demilitarized Zone which responds to the surrounding geopolitical conditions. Inspired by the Korean word Sanlimyok (forest bathing, which involves visiting a forest for relaxation and recreation), the project doubles itself above and underground, offering multiple ways to enjoy the bathing experience - a swim into a lake, a walk in the forest, a purification ritual in an intimate space. According to our vision, the site becomes the connecting point between North and South Korea, where visitors can enjoy their free time away from industrial noise and political tension. A round lake surrounds a forest island where an arched canopy lies – the entry point to the thermal bath below. Vaulted brick structures generates an array of spaces with different features (steam, rain, bath, relax, light) yet originated by the same round shape: the shape of a water drop.