Ginkonyu is a historic secret hot spring ryokan located in Kaminoyu Onsen, Yakumo Town, Futami District, Hokkaido, established in 1927 (Showa 2). As a member inn of the Japan Secret Hot Springs Association, it is highly regarded among hot spring enthusiasts.

The history of the hot springs dates back to ancient times. Originally, the hot water gushed out in a sandbar in the middle reaches of the Otoshibe River, where the indigenous Ainu people are said to have bathed. The late Edo period explorer Matsuura Takeshiro also introduced it in his 'Ezo Nisshi,' and during the Boshin War, wounded soldiers of the Shogunate forces recuperated here. On May 10, 1925 (Taisho 14), Kawaguchi Fukutaro struck abundant hot spring water through excavation. This date coincidentally marked Emperor Taisho's silver wedding anniversary, hence the name 'Ginkonyu' (Silver Wedding Hot Spring). The hot spring inn opened in 1927 (Showa 2).

The greatest feature is having 5 private hot spring sources and offering a 'hidden bath tour' across 11 different bathing areas. The source temperatures range from 60 to 95 degrees Celsius, with a total flow rate of 170 liters per minute (natural flow). The facility maintains 100% natural flowing hot spring water without any circulation, filtration, chlorine sterilization, or tap water mixing.

The spring quality varies by bathing area: indoor baths and family baths use a blend of 4 sources with about 10% spring water added, classified as sodium-chloride spring (weakly alkaline hypotonic hyperthermal spring). Outdoor baths and specialty baths like Katsura-no-Yu, Momiji-no-Yu, Donguri-no-Yu, and Sugi-no-Yu use a blend of 2 sources with 100% source water, classified as sodium-chloride/bicarbonate spring (neutral hypotonic hyperthermal spring).

The 'hidden bath tour' exclusive to overnight guests features 7 outdoor baths scattered along walking paths within the property, including the 'Tochi-no-Ki-no-Yu' made from hollowed-out Japanese horse-chestnut logs. The outdoor baths surrounded by trees allow guests to enjoy hot springs while experiencing nature through the four seasons.

The facility is a two-story wooden building with a garden of mainly maple and other deciduous trees on the premises. As one of the few pure Japanese-style hot spring ryokan in Hokkaido, the entire building is enveloped in the warmth of wood.

Day-trip bathing is available from 12:00 to 16:00, closed on Mondays (or the following day if Monday is a holiday). Note that day-trip bathing may be closed on irregular dates, so checking the official website is recommended. Fees are 800 yen for adults and 400 yen for children (ages 3 to elementary school), offering reasonable pricing.

The hot spring is effective for neuralgia, muscle pain, joint pain, frozen shoulder, motor paralysis, joint stiffness, bruises, sprains, hemorrhoids, chronic digestive diseases, chronic skin diseases, post-illness recovery, fatigue recovery, health promotion, weak children, chronic gynecological diseases, sensitivity to cold, cuts, and burns, making it a beloved therapeutic bath destination for many years.