Kogashima Onsen Kogashimaso is a secluded single-inn hot spring nestled on the shores of Lake Suigetsu, one of the Mikata Five Lakes in Wakasa Town, Fukui Prefecture. As a member of the Japan Association of Secluded Hot Spring Inns (Nihon Hitou wo Mamoru Kai), this inn features a charming atmosphere created by a relocated 150-year-old traditional farmhouse. The inn's name 'Kogashima' derives from a nearby mountain. Passing through the impressive thatched-roof gate, guests are greeted by a panoramic view of Lake Suigetsu. The spring water is classified as simple weak radioactive cold mineral spring (radon spring), with a source temperature of approximately 13-15 degrees Celsius, heated for bathing use. The men's bath includes a small free-flowing source water tub where guests can enjoy the colorless, transparent radon spring in its natural state. The outdoor baths offer views of the tranquil lake and surrounding mountains, with the autumn foliage season being particularly spectacular. The cuisine features fresh seafood from Wakasa Bay, including seasonal courses such as Wakasa pufferfish and Echizen crab. The brackish Mikata Five Lakes also offer seasonal fishing for freshwater shrimp, sea bass, and halfbeak, making this a popular retreat for both hot spring and nature enthusiasts.