Overview
Located within the serene mountain village of Yunomine Onsen in Wakayama Prefecture, Tsubo-yu is a tiny bathhouse that holds the title of Japan's oldest hot spring. Designated as a UNESCO World Heritage site, its significance in Japanese history and culture is monumental—but I was genuinely surprised when I saw it. It's so small!

Description
Tsubo-yu sits humbly beside a creek, encased in a modest stone hut. Only two people can bathe at a time, making it an unusually intimate experience. True to its name, which translates to "pot bath," the onsen is petite yet inviting. The water, known for its healing properties, has an intriguing feature—it changes color several times a day, ranging from clear to milky white, depending on the conditions.

Sitting in the warm waters feels like stepping back in time, a moment to imagine the pilgrims who once soaked here after traveling the Kumano Kodo trail. Its rustic charm, combined with the historical atmosphere, makes it a unique experience unlike any other hot spring I've visited.

The Story Behind Tsubo-yu
This small onsen is steeped in legend. Historically connected to the Kumano Kodo pilgrimage route, it was a place for travelers to cleanse themselves physically and spiritually. Emperors and monks alike sought its waters for their supposed healing qualities. Standing there, I couldn’t help but wonder how many lives this tiny spring had touched over the centuries.

While You're There
If you visit Tsubo-yu, you absolutely must explore the nearby Kumano Kodo pilgrimage trail. The trail leading to Kumano Hongu Taisha Shrine is particularly breathtaking. As you walk, you’ll be surrounded by towering trees and peaceful silence, broken only by the sounds of nature. It’s a deeply tranquil journey that pairs perfectly with the onsen experience.

Once your adventure is complete, treat yourself to a taste of the region’s famous mehari-zushi, a simple yet delicious snack of rice wrapped in pickled mustard leaves. It’s a traditional trail food and the perfect way to refuel after a day of soaking and exploring.

Access
Tsubo-yu is located in Yunomine Onsen, which can be accessed by bus from Shingu or Tanabe. It’s well worth the trip to experience a piece of Japan’s ancient history firsthand.

Osaka to Kii-Tanabe Station

By Train:

Take the JR Limited Express Kuroshio from Shin-Osaka Station or Tennoji Station to Kii-Tanabe Station.

The journey takes approximately 2 to 2.5 hours.

This train is covered by the JR Pass, but reservations are recommended.

Kii-Tanabe Station to Yunomine Onsen

By Bus:

From Kii-Tanabe Station, board the Ryujin Bus bound for Hongu Taisha or Yunomine Onsen.

The bus ride takes about 2 hours.

Alight at the Yunomine Onsen bus stop.

Opening hours and cost

6AM-9:30PM
770 yen entry cost