Mineral Hot Springs
Luxury

Ainsworth Hot Springs

British Columbia, Canada · nupika wu'u

Wade waist-deep through a horseshoe cave of 42°C mineral water above Kootenay Lake

Ainsworth's signature is the cave: a horseshoe-shaped tunnel roughly 45 metres long where you wade through waist-deep mineral water averaging 42°C (108°F), with steam, dripping mineral formations and a hotter inflow at the back. Outside, the main pool averages about 35°C and a cold plunge sits a few steps away, all overlooking Kootenay Lake and the Purcell Mountains. The resort posts an unusually detailed analysis led by calcium sulphate, sodium and magnesium carbonates, with lithium chloride, silica and small amounts of iron.

The springs are known to the Ktunaxa as nupika wu'u, spirit waters, and the resort now uses Ktunaxa language throughout, with a Ktunaxa Grill on site. Adult entry is 18 CAD, about 13 USD, first come first served, and hotel guests get longer pool hours. You drive straight in on Highway 31 between Nelson and Kaslo.

The honest downside: the cave is narrow and steamy, the far end is too hot for many people to stay in for long, and on busy days it fills shoulder to shoulder; public hours are also cut on some weekdays.

What's in the water

  • LithiumTrace lithium shows up in a handful of famous springs, Ojo Caliente the best known. Old spas marketed it heavily.
  • MagnesiumMagnesium-rich water feels soft and slightly slick. It is the mineral most bath-salt blends try to copy.
  • CalciumCalcium-rich springs build travertine: the white terraces of Pamukkale and the rock rims of countless wild pools.
  • SodiumSalty thermal water floats you a little higher and can sting fresh cuts.
  • ChlorideChloride springs are the salty, warm-holding waters common in Japanese onsen and coastal geothermal areas.
  • SilicaSilica turns water milky blue (Iceland) and leaves the skin feeling silky.
  • IronIron turns water and rock rust-orange or red-brown. It can stain light swimsuits.
  • SulfateSulfate springs are often clear and odorless, common in European spa towns.
  • PotassiumPotassium usually travels with sodium in mixed mineral water.

Sources

Hot springs near Ainsworth Hot Springs

Dewar Creek Hot SpringsOff the GridDewar Creek Hot SpringsBritish Columbia, CanadaBoiling vents and one small tub at the end of a 9.6 km Purcell wilderness hikeWild pool · FreeOff the GridSherwin Hot SpringBritish Columbia, CanadaWild poolLuxuryNakusp Hot SpringsBritish Columbia, CanadaVillage-owned forest pools in the Kuskanax Valley, with cheap Wednesday winter swimsPublic bath · 40°C / 104°F · $Off the GridClothing OptionalRam Creek Hot SpringsBritish Columbia, CanadaLukewarm terraced pools in a quiet ecological reserve, usually all yoursWild pool · 32°C / 90°F · FreeLuxuryFairmont Hot SpringsBritish Columbia, CanadaBig, odourless calcium springs at a family ski-and-golf resort in the Columbia ValleyResort · 39°C / 102°F · $$Off the GridHalfway River Hot SpringsBritish Columbia, CanadaHand-built wooden tubs and a riverside pool, free to soak, cash to campWild pool · 49°C / 120°F · Free

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