Nanasawa Onsen: Hot Spring Guide & Visitor Access

Spreading along the eastern foot of Mount Oyama west of Atsugi, Nanasawa Onsen is a quiet spa cradled in the hills of East Tanzawa. It was already a popular healing spa by the late Edo period and still keeps a calm, secluded atmosphere. Though only about an hour by train and bus from Shinjuku or Yokohama, many visitors are surprised to find such a hidden village so close.

Highlights

• Strong alkaline water with a slippery feel, well known as a beauty water
• A smooth bathing sensation thanks to a high content of moisturizing metasilicic acid
• Old temples scattered through the hills, such as Kannonji and Hinata Yakushi
• The nature of the hills, laced with quiet hiking courses

Enjoying the Seasons

Surrounded by rural hills, the area lets you feel the turn of the seasons up close. Spring brings budding colors with fresh greenery, early summer offers deep green, and autumn glows with foliage, making it ideal for combining hiking and bathing. In winter the silky alkaline water feels all the more welcome under clear air.

Access and Basic Information

• From Hon Atsugi Station on the Odakyu Line, take a bus toward Nanasawa for twenty five to thirty minutes, alight at stops such as Nanasawa Onsen Iriguchi or Nanasawa Byoin Iriguchi, and walk about fifteen minutes
• About thirty minutes by car from the Atsugi interchange
• Some inns, such as the Fukumotokan, accept day bathing. Day use at Fukumotokan is around one thousand three hundred yen per person. Confirm hours in advance
• Main water type is alkaline simple spring, a high pH strong alkaline water known as a beauty spring

Practical Travel Notes

• The best seasons are the fresh green of May and June and the autumn leaves of November, which pair well with hikes up Mount Oyama or to Hinata Yakushi
• Buses run infrequently, so checking the timetable in advance is recommended. Some inns offer a pickup service
• Combining a visit to a nearby old temple such as Hinata Yakushi with a hike makes a half day to full day plan. Add a bath to savor the hills at leisure
• Budget wise, day bathing starts from the low thousands of yen, while an overnight stay centers on quiet inns where strong alkaline water flows from the source

A Quick Tip

Nanasawas water is praised for leaving skin smooth, but pairing it with a walk through the surrounding hills doubles the appeal. Visit a nearby old temple such as Hinata Yakushi first, then soak, and both mind and body will unwind. The alkaline water warms you well, so remember to rehydrate after your bath.