Magoroku Onsen is a secluded hot spring inn located in the deepest reaches of Nyuto Onsen-kyo (Nyuto Hot Spring Village) in Semboku City, Akita Prefecture, renowned as one of Japan's most remote hot spring retreats. Nestled at an elevation of approximately 700 meters along the Sendatsu River in the foothills of Mount Nyuto within Towada-Hachimantai National Park, it is surrounded by pristine beech forests that create an atmosphere of profound tranquility.

The hot spring was discovered in 1902 (Meiji 35) by agricultural engineer Mr. Sakurai and opened as a healing resort in 1906 (Meiji 39) by Mr. Taguchi Kyukichi, giving it over 120 years of history. Known affectionately as "Yama no Kusuri-yu" (Mountain Medicine Hot Spring) due to its therapeutic properties, Magoroku Onsen particularly retains the traditional ambiance of a therapeutic hot spring resort among the Nyuto Onsen-kyo establishments.

After temporarily closing in 2022 due to lack of successors and an aging workforce, operations were taken over by Tosho-ji company from Daisen City, which undertook extensive renovations. Day-use bathing reopened in February 2025, followed by the grand opening on April 26, 2025, under the new name "Magoroku Onsen Rokuan."

While maintaining its charm as a hidden hot spring, the renovated facility has been transformed into a modern and sophisticated retreat. With only six guest rooms, it offers an exclusive and private experience. The unique village-style layout with separate lodging and bathing buildings allows guests to directly experience the magnificent nature of Nyuto as they move between structures.

The hot spring features 3-4 different source springs, each offering distinct water qualities. Notably, "Ishi-no-Yu" (Stone Bath) is characterized by its mystical blue-colored water that emerges from beneath the bathing area. The water color changes with weather conditions - when cloudy, rain is likely the next day, and when clear, fair weather is expected, making it a natural weather forecaster for hikers. Additionally, Magoroku Onsen is the only facility in Nyuto Onsen-kyo equipped with a barrel sauna, allowing guests to enjoy both hot spring bathing and sauna experiences.

The surrounding area features the clear streams of Sendatsu River and offers seasonal natural beauty. Spring brings fresh greenery and mountain vitality, summer showcases lush deep mountains, autumn displays vibrant foliage, and winter presents scenes of gently falling snow. The adjacent Kuroyu Onsen is just across the river and accessible on foot.