Sakinoyu Seaside Open-Air Bath in Shirahama | Soaking in 'Muro-no-Yu,' One of Japan's Three Ancient Hot Springs, to the Sound of Waves

Sakinoyu in Shirahama: A Seaside Open-Air Bath Where the Sea and Hot Spring Meet

Sakinoyu, located in the Yuzaki area of Shirahama Town, is a seaside open-air bath set on rocky shores with the Pacific Ocean stretching out beyond. Just past the edge of the tub lies the open sea, and the sound of waves and scent of saltwater drift in together with the steam of the hot spring.

Among the many baths of Shirahama Onsen, this is a symbolic one that many visitors specifically seek out. Rather than simply "taking a bath," the experience feels closer to "bathing in hot water and sea breeze on the shore."

Shirahama Onsen: One of Japan's Three Ancient Hot Springs

Shirahama Onsen is often listed—alongside Arima Onsen (Hyogo) and Dogo Onsen (Ehime)—as one of Japan's Three Ancient Hot Springs. It appears in old records under the name "Muro-no-Yu," and tradition holds that Empress Saimei made imperial visits here as far back as the 7th century.

This is also a land where travelers walking the Kumano Kodo pilgrimage routes have long soothed their fatigue in the hot springs. Thinking of this bath together with Yunomine Onsen along the old route—as part of the Kumano region's broader tradition as "a land for restoring body and mind through hot springs"—can subtly shift how you see your journey.

Three Ways to Enjoy Sakinoyu

1. Let Your Mind Drift to the Sound of Waves

The charm of Sakinoyu lies more in "feeling" the scenery than "looking at" it. Gazing at the sea and giving yourself over to the rhythm of wind and waves is time that lets you forget the hustle of sightseeing.

2. Choose a Time of Day for a Different Face of the Sea

The clear light of morning, the blue sea at midday, the reddish sky of evening—the seaside bath takes on strikingly different expressions depending on the time. If your schedule allows, visiting at different hours to enjoy the changing scenery is highly recommended.

3. The Post-Bath Stroll Is Part of "Sakinoyu Time"

After bathing, try taking a slow walk around the Yuzaki area. The sea breeze feels just right on a warmed body, and you'll find foot baths, seaside lanes, and other little detours unique to a hot spring town.

What to Know Before You Visit

• As an open-air bath set in nature, it can be affected by weather and waves. Bathing may not be possible on rough days, so check the official information before you go for peace of mind.
• Please check the latest information for opening hours, fees, closed days, and whether towels are available.
• The wet rocks underfoot can be slippery. Walk slowly to and from the changing area and around the tub.
• Follow the on-site guidance for managing valuables and bathing etiquette. The seaside setting offers wonderful openness, but consideration for others is just as important.

Seaside Scenery in Shirahama to Pair with Sakinoyu

Shirahama Town is dotted with nearby spots that showcase ocean views, such as Senjojiki and Sandanbeki. Soaking at Sakinoyu and then walking along the coastline afterward lets you enjoy "the hot spring and the sea" as one continuous experience.

If you have time, sampling local fish at a nearby restaurant makes a wonderful finish. Even on a journey heading toward Kumano, stopping at Shirahama at the beginning or end of your trip helps give the journey a pleasing rhythm.

Summary | Time to Feel the Ancient Hot Springs and the Timeless Sea

Sakinoyu in Shirahama Town is a place where you can experience, all at once, the history of Shirahama Onsen—one of Japan's Three Ancient Hot Springs—and the openness unique to a seaside open-air bath. Soaking in the hot water while listening to the waves is sure to be a memorable moment, whether partway through your Kumano journey or as its closing chapter.

Check the latest information in advance, and plan a visit that fits the weather and your condition without overdoing it.

Image: 川湯温泉　仙人風呂 (via (公社)和歌山県観光連盟)