Dubbed "okuzashiki (secluded room)" in the Senshu area, Okumizuma Onsen (hot spring) is located at the foot of Mt. Katsuragi, close to the border with Wakayama Prefecture. This onsen has a natural hot spring bath overlooking mountain streams. Okumizuma Onsen is a highly concentrated natural sodium spring, believed effective for various ailments such as nerve pain, joint pain, chronic digestive disorders, and chronic skin diseases. Called a "miraculous spa," Okumizuma Onsen has been enjoyed as a curative spa by many people since olden times. It is also popular among women who want achieve smooth skin. Also impressive is the seasonal beauty of nature, such as cherry blossoms in spring, fresh greenery in early summer, fireflies in summer, and beautifully colored foliage in autumn. At this hot spring, guests can stay overnight, and can also make a day trip, enjoying meals and bathing. In the vicinity are historic sites, such as Mizumadera Temple, associated with Onatsu and Seijuro (elopers in the Edo period), and the national treasure Kuginashido (Koonji Temple). They are recommended places to drop in and take a rest while out strolling.