Takayu Onsen Tamagoyu is a long-established hot spring ryokan located at an elevation of approximately 750 meters on the slopes of the Azuma Mountain Range in Fukushima City, Fukushima Prefecture. While Takayu Onsen itself was discovered over 400 years ago by a hunter named Shishido Goemon, Tamagoyu was founded in 1868 (Meiji 1) when village headman Goto Kojibei built a shelter for people suffering from intractable diseases. The thatched-roof bathhouse Tamagoyu, with over 150 years of history, retains its original appearance from the founding era and is recognized as an iconic landmark of Takayu Onsen. The water is classified as an acidic sulfur-containing (hydrogen sulfide type) aluminum-calcium sulfate hot spring (sulfur spring) with a strongly acidic pH of 2.8, a source temperature of 44 degrees Celsius, and characteristically milky-white sulfurous water. Over 3,000 liters per minute naturally well up from nine source springs, flowing entirely by gravity using the natural terrain elevation, maintaining 100% pure free-flowing source water with absolutely no heating or dilution. The bathing facilities include the historic thatched-roof bathhouse Tamagoyu, the outdoor bath Tenkei no Yu (alternating by gender daily), the large bath Taki no Yu, the indoor bath Senki no Yu, the private outdoor bath Seon, and a relaxation foot bath. Day-trip bathing is available in two sessions: daytime (11:00-14:00) and evening (16:00-20:00), priced at 1,000 yen for adults with a 90-minute limit. Lunch service featuring soba and udon is available on weekends and holidays.