Jurassic Onsen Churaumi no Yu

Jurassic Onsen "Churaumi no Yu" is a natural hot spring inside the Orion Hotel Motobu Resort & Spa in Bise, Motobu Town, Okinawa, next to the Okinawa Churaumi Aquarium. The water is drawn from 1,500 meters underground and originates from Jurassic-period strata over 200 million years old, which is the source of the name "Jurassic Onsen." The bathing area on the fifth floor of the Ocean Wing offers views of the emerald-green sea, the horizon, and Ie Island. The hotel is also the official partner hotel of Junglia Okinawa, a theme park that opened in 2025.

The spring is a sodium chloride strong-salt hot spring (hypertonic, neutral) with a high salt concentration close to that of seawater. The salt forms a film on the skin that retains heat well, and the water is said to help with neuralgia, muscle and joint pain, sensitivity to cold, and fatigue recovery. Because the source temperature is only about 30.9°C, the water is heated; the hotel officially states that in addition to heating, the water is filtered by recirculation and disinfected. It is therefore not a free-flowing (kakenagashi) spring. The pH value is not disclosed.

The bath has an indoor pool and a semi-open-air bath, plus a sauna (dry on the men's side, steam on the women's side) that alternates between men and women on different days. There are 20 washing stations on each side and a powder room. Day-trip bathing costs 2,150 yen for adults (bathing tax included), 1,000 yen for elementary school children, and is free for younger children. The bath operates in two sessions, 6:00-10:00 and 15:00-24:00, and is open year-round. As a resort hotel it also offers roughly 200 parking spaces, several restaurants, pools, and a fitness room.