Iiyama Onsen: Day-Use Hot Spring Baths & Prices

Spreading along the Koayu River at the eastern edge of the East Tanzawa foothills in the northwest of Atsugi, Iiyama Onsen is an old spa where inns are scattered by the water. Its strong alkaline water, with a high pH, softens the skin, and it has long been cherished as a beauty water. Nearby stands the Iiyama Kannon, a temple of the Bando pilgrimage, preserving the mood of a village where faith and bathing are intertwined.

Highlights

• Strong alkaline water with a high pH, a silky beauty spring
• Iiyama Kannon Chokokuji, the sixth temple of the Bando thirty three Kannon pilgrimage
• The charm of inns along the Koayu River, once called a hidden retreat of Tokyo
• A row of cherry trees along Daimon Street and hydrangeas in early summer

Enjoying the Seasons

In spring the cherry trees of Daimon Street leading to the Iiyama Kannon come into full bloom, and in the evening they are lit up for night viewing. Early summer brings hydrangeas and autumn brings foliage, with the temple and riverside nature coloring each season. After strolling through the famous blossoms, this is a place that suits soaking slowly in the silky alkaline water.

Access and Basic Information

• From Hon Atsugi Station on the Odakyu Line, take a bus bound for Kami Iiyama or Miyagase and alight at stops such as Iiyama Kannon Mae or Iiyama Onsen Iriguchi, a ride of a little over twenty minutes
• Close enough to reach from the metropolitan area in about an hour, and known as a hidden retreat of Tokyo
• Some inns, such as the Motoyu Ryokan, accept day bathing. Check hours and plans in advance, as they vary
• Main water type is alkaline simple spring, known for its high pH strong alkaline water

Practical Travel Notes

• The best time is the cherry blossoms of late March to early April. The row of cherry trees on Daimon Street leading to the Iiyama Kannon is also lit up at night. Hydrangeas in early summer and foliage in autumn are further highlights
• The cherry blossom season is especially popular, so to avoid crowds a weekday or morning visit is best
• Iiyama Kannon Chokokuji is a flower temple selected among Kanagawas hundred famous flower spots. A visit plus a riverside stroll takes about half a day, and adding a bath makes an easy full day plan
• Budget wise, day bathing starts from around one thousand yen, while an overnight stay centers on inns where strong alkaline water flows from the source

A Quick Tip

The cherry blossom season is especially popular, so to avoid crowds a weekday or early visit is best. Soaking after a visit to the Iiyama Kannon lets you spend a day in true old fashioned healing spa style. The strong alkaline water leaves skin smooth and warms you well, so remember to rehydrate after your bath.

Practical Information for Your Visit

• Location of the hot spring area: Iiyama, Atsugi City, Kanagawa Prefecture (at the foot of the Eastern Tanzawa mountains, along the Koayu River)
• Spring quality: Strongly alkaline water with a pH of 11.3. A beauty bath that softens rough skin
• Current inn: The one inn currently operating is "Motoyu Ryokan" (4916 Iiyama, Atsugi City / Tel. 046-242-0008). The former Ryokan Atsugi Museum and Furusato no Yado have closed
• Day-use bathing: Drop-in bathing without a meal is not accepted. To enjoy the water on a day trip you take a plan that includes a meal; the dinner plan runs from 16:00 to 22:00 and starts at around 12,000 yen
• Bath layout (Motoyu Ryokan): One indoor bath each for men and women, one open-air bath each for men and women, and one private (family) bath. These include a mountain-stream open-air bath, a utase-yu (cascading water) open-air bath, and a "tanuki" bath
• Water treatment: Whether the water is diluted, heated or recirculated is not published. If this matters to you, the surest approach is to ask when you book
• Parking: 100 spaces for ordinary cars at Motoyu Ryokan
• Access (by bus): About 23 minutes from bus stop No. 5 at the north exit of Hon-Atsugi Station on the Odakyu Line, taking a bus bound for "Kami-Iiyama" or "Miyagase" (routes Atsu 18 to Atsu 22), then about a 4-minute walk from the "Iiyama Onsen Iriguchi" stop
• Access (by car): About 21 minutes (9.1 km) from the Atsugi IC on the Ken-o Expressway. About 20 minutes from the Ebina SA on the Tomei Expressway
• Iiyama Kannon Hasedera Temple: Open to worshippers 8:30-16:30 (5605 Iiyama, Atsugi City / Tel. 046-241-1635). In addition to Iiyama Kannon's own goshuin stamp book, three types of stamp books for the Bando Thirty-Three Kannon pilgrimage are available
• Time needed: Half a day for a temple visit and a riverside walk, or a full day if you build in a day-use plan with a meal
• Budget guide: A day trip with a meal plan starts at 12,000 yen. If you only visit the temple and take a walk, transport costs are all you need
• To avoid crowds: The cherry blossom season (late March to early April) is the busiest. Weekdays or morning visits are recommended
• In the rain: The hot spring and the meal at the inn are indoors, so they are unaffected by the weather. The approach to Iiyama Kannon can be walked in the rain, but the stone steps become wet and slippery
• Footing and clothing: Stone steps lead up to the grounds of Iiyama Kannon, so wear comfortable walking shoes. As it lies among the mountains, it feels cooler than the city center
• Strollers and wheelchairs: Stone steps lead to the Kannon hall at Iiyama Kannon, so it is not suited to wheeled access. Consult the inn in advance about its facilities
• Nearby: Iiyama Hakusan Forest Park, beautiful in autumn, is close by and can be walked in combination with a temple visit

Sources of Information

The spring quality of Motoyu Ryokan (strongly alkaline water with a pH of 11.3), the layout of indoor, open-air and private baths, the fact that drop-in bathing alone is not accepted and that day trips use a plan including a meal (dinner plan 16:00-22:00, from 12,000 yen), the 100 parking spaces, the address and telephone number, the bus routes and journey time from Hon-Atsugi Station, and the driving time from the Atsugi IC on the Ken-o Expressway were confirmed on the Motoyu Ryokan page of the Atsugi City Tourism Association's "Atsugi Kanko Navi." The point that the source's pH of 11.3 is the highest value, and the journey time of about 20 minutes from the Ebina SA, are based on statements on Motoyu Ryokan's official website.

The facts that Iiyama Onsen lies along the Koayu River at the foot of the Eastern Tanzawa mountains and that its source is strongly alkaline, that Ryokan Atsugi Museum has closed, and that Iiyama Kannon and Iiyama Hakusan Forest Park are nearby, are based on the guides to Iiyama Onsen and the Atsugi Onsen district published on the official websites of Atsugi City and Kanagawa Prefecture. The closure of Furusato no Yado was confirmed from publicly available information on the inn ceasing operations.

The visiting hours of Iiyama Kannon Hasedera Temple (8:30-16:30), its founding by the monk Gyoki in 725 (Jinki 2), its status as the sixth temple on the Bando Thirty-Three Kannon pilgrimage, the goshuin stamp books offered, and the roughly 3,000 cherry trees are based on statements on the official website of Hasedera (Iiyama Kannon). The temple marking 1,300 years since its founding in 2025 (Reiwa 7) and its selection for the "50 Scenic Spots of Kanagawa" and the "100 Famous Flower Spots of Kanagawa" are based on the Atsugi City Tourism Association's information on Iiyama Kannon.

Operating status, prices and hours are subject to change, so please check the official information before you set out.