Yunohama Open-air Onsen

In short

Yunohama Open-air Onsen is an open-air hot spring entered in swimwear, located at Mamashitaura on the west coast of Niijima Island. It is known for its appearance reminiscent of ancient Greek architecture, built from the island's specialty Koga stone. The spring water is a strong sodium-chloride spring, and you can look out over the sea from the baths along the coast.

• ​Temple-style Architecture​​: The landmark is a building reminiscent of the Parthenon, utilizing the rocky coastal area.
• ​Six Baths of Various Sizes​​: You can soak in the hot water while gazing at the vast ocean. Even without swimwear, you can use the adjacent footbath.
• ​Sunsets and Starry Skies​​: Located on the west side of the island, you can enjoy sunsets in the evening. At night, you can enter the onsen under a starry sky.

History and Highlights

Yunohama Open-air Onsen is an open-air hot spring located at Mamashitaura on the west coast of Niijima Island. "Mama" is an archaic word meaning cliff, so Mamashita means the coast below the cliff. It is the same word as the "mama" in the Shiromama Cliffs of Habushiura.

In front of your eyes is a building reminiscent of ancient Greek architecture, made of the island's specialty Koga stone. Utilizing the rocky shore along the coast, this Parthenon-style building itself houses the open-air baths. The foundation lava is from the Setoyama volcano located south of Honson. There are six baths of various sizes.

The spring quality is a strong sodium-chloride spring, reputed for warming the body thoroughly. It contains large amounts of seawater components and is water with a high salt concentration. It is free-flowing (kakenagashi) without the use of chlorine, with water added for temperature adjustment. Because it is not managed for drinking, please do not drink it.

Because it is a mixed-gender onsen, you enter wearing swimwear. Bathing in bathing robes or bath towels is not permitted.

Viewing and Experiencing Tips

• ​Baths with an Ocean View​​: Soak in the hot spring while looking out over the vast ocean. Since it is on the west side of the island, you can enjoy a beautiful sunset in the evening.
• ​Nighttime Onsen​​: It can also be used at night, allowing you to enjoy the hot spring under a starry sky. If the weather is good, you might even see the Milky Way.
• ​Footbath​​: Even without swimwear, you can soak in the attached footbath. If you forget your swimwear, you can purchase it at souvenir shops or clothing stores on the island. There are no rentals.

Exploration Tips

It is about a 10 to 15-minute walk from Niijima Port. At the entrance of the hot spring, there are men's and women's changing rooms, dial-lock lockers, and paid warm-water showers. Restrooms and vending machines are located outside the onsen. Parking is available next to the hot spring entrance and at a second parking area near Torigashima. Bathing may not be possible on days with strong westerly winds in winter. At the nearby Mamashita Coast, you can explore tidal pools on the hot spring side. During low tide, a path leading to Torigashima also appears. Be careful of rip currents that form on the south side of Torigashima. On the plateau behind, there is Mamashita Onsen, which also has sand steam baths. Habushiura is approximately 3.4 kilometers east-northeast.