"Peiron Onsen" is a bathing facility on the second floor of Aioi Haku Ryu Castle, a roadside station in Aioi City, Hyogo Prefecture. Its biggest attraction is the open-air bath with spectacular views overlooking the calm sea of Aioi Bay and the factories across the water. After working up a thorough sweat in an authentic dry sauna, you can cool your whole body in a cold plunge bath and enjoy an exceptionally open-air rest while feeling the sea breeze. It is also known as a sacred place for Showa-era pop songs, and the dining area serves local specialties such as oyster dishes.