Yutoro Sagasawa no Yuゆとろ嵯峨沢の湯

Yutoro sits at 吉浜1191 on Route 135, roughly equidistant between Yugawara and Manazuru stations at about two kilometres from each - not walkable from either without the bus, but the 花見 (Hanami) bus stop is one minute on foot from the entrance. By car, 30 free parking spaces and simple road access make it the natural choice for Tokyo-day-trip drivers heading along the Sagami Bay coast. The setting is the facility's first argument: a hillside above mandarin orchards, isolated from the main Yugawara valley, with an unobstructed panorama of Sagami Bay that stretches toward the Izu Peninsula on clear days. The outdoor deck between sauna rounds is reason enough to stay an extra hour.

The facility runs two named baths on a daily male/female rotation: ささはなの湯 and こちょうの湯. ささはなの湯 centres on 大滝の湯, a four-metre waterfall cascade bath that delivers genuine pressure across the shoulders and upper back; alongside it, a 気泡の湯 (bubble bath) and an indoor hinoki cypress bath, all oriented toward the bay. こちょうの湯 takes a different character - a 洞窟風呂 (cave bath) with steam rising from the rocks and its own smaller waterfall, plus indoor baths with sea views. Both sides have outdoor deck access. If you prefer one over the other, the rotation schedule is on the facility's official site; otherwise the private rental baths (貸切風呂) are available regardless of the day for around ¥3,500 per 120 minutes, bookable at the front desk.

The spring is a self-sourced 単純温泉 - the facility pumps its own water from 1,100 metres underground, a separate provenance from the shared municipal 混合泉 distribution that most other Yugawara day-use facilities draw from. It emerges at 44.8°C (a high-temperature spring, just above the 42°C threshold), with a weakly alkaline character at around pH 8.0 and 760 mg/kg total dissolved solids. The water is colorless and odourless; multiple visitors describe a smooth, silky texture that lingers on the skin, and drinking spring water is available inside the building - a marker of the spring's overall quality. The water handling is 循環 with chlorination, confirmed by Yukoyuko (which explicitly marks 源泉かけ流し as unavailable) and Supersento. Niftyonsen's listing says 'かけ流し,' but this conflicts with both other aggregators and is likely a data entry error - the same pattern seen at Miyakami no Yu and New Welcity.

The Finnish sauna runs around 80-90°C adjacent to a cold plunge bath, with the outdoor terrace for recovery between rounds. Two restaurants handle meals, skewing toward fresh seafood - useful if you want to extend a half-day soak into an afternoon and dinner. Six overnight cottages (ゆとろコテージ) are available if you want to stay, each with a private onsen bath from the same spring; day-use guests use the shared baths only. The facility provides shampoo, conditioner, body soap, and hairdryers; bring your own towel or rent at the counter.

Admission is ¥1,350 per adult (middle school and above), ¥650 per elementary school child, with one infant per adult free. Aggregators show prices from ¥1,255 to ¥1,380, likely reflecting tax-exclusive vs tax-inclusive reporting and periodic increases; the Kanagawa prefecture tourism page states ¥1,350. No significant peak surcharges have been documented. The facility is closed Thursdays except holidays; open every day in March and August. Weekday hours are 10:00-21:00 (last entry 20:30); weekends and holidays run until 22:00 (last entry 21:30).

In the Yugawara onsen lineup, Yutoro holds the scenic-variety slot. It offers the most theatrically differentiated bath environments in the area - waterfall, cave, bubble, sauna, private rental, drinking spring - in the best hilltop setting, and is the natural recommendation for car-based visitors wanting multiple bathing environments in a single session. For the purest mineral water, Mamanenoyu at ¥300 with its 純温泉 certification wins on water quality. For novelty, Miyakami no Yu has Yugawara's first carbonated spring. For scale, New Welcity holds the largest outdoor pool and a genuine kakenagashi stone bath. Yutoro wins on setting, bath variety, and the sauna-deck-view combination.

住所: 神奈川県足柄下郡湯河原町吉浜1191

電話番号: 0465-62-2688

営業時間: Weekdays 10:00-21:00 (last entry 20:30); weekends and holidays 10:00-22:00 (last entry 21:30)

タオル: Towel rental available (charged separately). Shampoo, conditioner, body soap, and hairdryers provided.

浴槽の種類: 露天風呂, 内湯（ひのき）, 大滝の湯（4m打たせ湯）, 気泡の湯, 洞窟風呂, フィンランドサウナ, 水風呂, 貸切風呂, 飲泉

源泉: 湯河原温泉 自家源泉（吉浜）

泉質: 弱アルカリ性低張性高温泉 単純温泉

源泉温度: 44.8°C

pH: 8

温泉の取り扱い: 循環

「温泉は泉質が良くて、肌がツルツルピカピカになりました」

The spring quality is excellent - skin came out smooth and luminous.

「なめらかな肌触り」

A silky, smooth texture on the skin.

「周囲はみかん畑が連なり、相模湾を見渡す眺望も自慢です」

Surrounded by mandarin orange groves, with a panoramic view of Sagami Bay we're proud of.

「地下約千百十メートルから汲み上げる自家源泉」

A self-sourced spring pumped from about 1,100 metres underground.

「飲泉も可能です」

Drinking the spring water is also available.

「男女日替わり交替の浴場が2つあり、露天風呂のしつらえを大きく変えています」

Two baths swap daily between men and women - each with a dramatically different outdoor design.

「かけ流しではありません」

This is not a source-flow bath.

複数のプラットフォームで収集した情報に矛盾があった箇所です。

• Water handling - Niftyonsen 'かけ流し' vs Yukoyuko/Supersento 循環: Yukoyuko explicitly marks 源泉かけ流し as ✕ and lists 循環 + 塩素消毒. Supersento confirms 循環. Niftyonsen says 'かけ流し' - this conflicts with both aggregators and is treated as a data entry error, consistent with the same pattern found at Miyakami no Yu and New Welcity. Published as 循環. Surugabank's note of 'no dilution needed' (加水不要) refers to the 加水 dimension only and does not contradict 循環.
• 自家源泉 vs 混合泉 - self-sourced spring provenance: Unlike most Yugawara day-use facilities (Kogome no Yu, Miyakami no Yu, New Welcity, Mamanenoyu) which draw from the municipal 混合泉 distribution, Yutoro operates its own spring pumped from 1,100m below the property at ~320 liters/min. This 自家源泉 distinction means the spring character is traceable to a single geological source. The spring is registered as 湯河原温泉 but is a separate source from the town's shared supply network. Rubric §7.18 documents this pattern.
• Admission price variance across aggregators: Niftyonsen and Yukoyuko list ¥1,255; Kanagawa pref official tourism page and Surugabank list ¥1,350; Supersento lists ¥1,380. The ¥1,255 figure likely reflects a stale tax-exclusive price or an older price tier. The ¥1,380 figure may reflect the most recent increase. Using ¥1,350 as the current stated price from the Kanagawa pref official source. Monitor for changes.
• Official site TLS certificate error: yutoro.co.jp returned ERR_TLS_CERT_ALTNAME_INVALID on both http and https fetch attempts. Direct spring certificate data (water handling notice, 温泉分析書) could not be retrieved. Spring data sourced from Niftyonsen and Surugabank cross-reference. Water handling confirmed via Yukoyuko and Supersento rather than the official notice poster.
• Bath rotation - kanji and names: Two rotating baths named ささはなの湯 and こちょうの湯 confirmed via multiple sources. Kanji not verified from official site (TLS error). ささはな may be 嵯峨沢の花, こちょう may be 胡蝶 (butterfly). The guide page refers to them by hiragana. Check official site when TLS resolves and update if kanji differ.
• Tattoo policy: No official statement found in research. Niftyonsen review corpus includes '刺青禁止が守られていない' (tattoo ban not enforced) - the phrasing implies a not_permitted policy exists but enforcement is lax. Published as not_permitted (standard Japanese onsen position). Verify with facility directly if needed.

• ゆとろ嵯峨沢の湯 公式サイト
• Niftyonsen - ゆとろ嵯峨沢の湯
• Surugabank 井伊部長の温泉グルメ探訪
• Supersento - ゆとろ嵯峨沢の湯
• ゆこゆこ お風呂・温泉情報
• 神奈川県 Feel SHONAN 観光スポット