Akigawa Keikoku Seoto-no-Yu Spa is in Akurino, to the west of Tokyo. It's a simple facility, and its elegant design blends well with the beautiful natural surroundings of the Akigawa Valley. The onsen features a single indoor bath, a sauna, and a stone ringed outdoor bath on the veranda with a view of the forest. Seoto-no-Yu's alkaline water is great for the skin, leaving it feeling slightly slippery. The onsen also has a traditional kaiseki banquet style restaurant featuring local fare and an attached shop selling regional goods. The spa's great for day visits and overnight stays alike.