The New Mineral Baths are part of Krynica-Zdrój's old spa infrastructure, the kind of building that explains why this mountain town became fashionable in the first place. Even if you are not taking treatments, the architecture belongs to the resort promenade story.
See it while walking between the pump rooms, parks, and older spa houses. Krynica is best understood as a composed spa landscape rather than a single attraction, and this is one of its useful pieces.