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♨ Hot Spring

Tsurumaki Onsen Kobo no Satoyu — Station-Side Hot Spring Near Tanzawa

A municipal day-trip hot spring just 2 minutes from Tsurumaki-Onsen Station on the Odakyu Line. Known for Japan's highest calcium content, it is the go-to post-hike bath for Tanzawa and Oyama hikers.

Published: 2026-03-27
Access

Tsurumaki-Onsen Station

2-minute walk from Odakyu Line Tsurumaki-Onsen Station

Hours

10:00–21:00 (last entry 20:30)

Price

2 hours ¥800 (full day ¥1,000)

Closed

Mondays (following day if Monday is a holiday)

Reservation

Walk-in OK

Overview

Kobo no Satoyu is a municipal day-trip hot spring in Hadano City, Kanagawa Prefecture, located just a 2-minute walk from Tsurumaki-Onsen Station on the Odakyu Line. Tsurumaki Onsen has been known as a healing spring for centuries, boasting one of the highest calcium contents of any hot spring in Japan.

Its convenient location near Tanzawa and Oyama trailhead access stations makes it a favorite post-hike stop for many hikers. The affordable pricing is another attractive feature.

Facility Information

Baths

  • Indoor bath: Main bathing pool (separate for men and women)
  • Outdoor bath: Rock bath
  • Spring quality: Calcium-sodium chloride spring
  • Benefits: Relief from nerve pain, muscle aches, joint pain, and fatigue

Pricing

Category2 HoursFull Day
Adult (junior high and above)¥800¥1,000
Child (elementary school)¥400¥500

*Discounts available for Hadano City residents

Rest Facilities

A spacious tatami-mat rest area is available for relaxing after your bath. A light meal corner offers simple meals.

Access

From the ticket gates of Tsurumaki-Onsen Station on the Odakyu Line, head toward the south exit. The facility is about a 2-minute walk with clear signage.

  • Train: About 70 minutes from Shinjuku Station on the Odakyu Line → get off at Tsurumaki-Onsen Station
  • Car: About 15 minutes from Hadano-Nakai IC on the Tomei Expressway (parking available)

Tip: After descending the Okura Ridge from Tanzawa, you can reach here from Shibusawa Station in just one stop (about 3 minutes) on the Odakyu Line. A perfect ending to your hike.

Highlights

Two Minutes from the Station

When your legs are tired from hiking, the last thing you want is a long walk to a bath. The ultra-short distance from the station is a huge advantage.

Affordable Municipal Hot Spring

At ¥800 for 2 hours, it is very reasonably priced compared to private day-trip hot springs in the area. Plenty of time for a quick post-hike soak.

Calcium-Rich Spring Water

Tsurumaki Onsen’s calcium content is among the highest in Japan. The mineral-rich water is said to be especially beneficial for tired muscles and joints — ideal for hikers.

Nearby Trails

  • Mt. Tanzawa (1,567m): Popular via the Okura Ridge (Baka-One). Accessible from Shibusawa Station, one stop away
  • Mt. Oyama (1,252m): A sacred mountain accessible by bus from Isehara Station. Cable car available for beginners
  • Tanzawa Main Ridge Traverse: The iconic traverse connecting Tonotake, Tanzawasan, and Hirugatake