Nestled in Yufu City, Oita Prefecture, Tsukahara Onsen is a secluded hot spring renowned for its highly acidic waters—among the strongest in Japan. The sulfur-scented, mineral-rich waters, often referred to as the “Fountain of Life,” tighten the skin while deeply warming the body from within.Set amidst lush mountain scenery, the open-air baths offer breathtaking seasonal views. The surrounding area also features scenic walking trails and delicious local dining spots, making it the perfect getaway for relaxation and rejuvenation.