I tried the serene and restorative new wild sauna at Scotland's best hotel

This luxury Perthshire destination doesn’t do things by halves

I’ve tried loads of Scotland’s wild saunas, from one in Arran to another at the more incongruous location of Leith Links.

However, I should’ve realised that the newest addition, from five-star hotel Gleneagles, would be no ordinary example.

We’re driven there by Fraser in a Landrover Defender. Our destination is the estate's wellness and recreation attraction, Frandy Water, which is populated with trout and also offers fly-fishing, Canadian canoeing and kayaking. On the edge of the loch, in a secluded spot, is the beautiful shingle-covered wood-fired sauna. It resembles a posh hobbit house and is much larger than your usual converted horse-box.

Inside, and they’ve made it five-star. There’s a welcome area, with homemade protein bars, hot drinks, fruit and nuts. And, a spacious changing annexe, where you’ll find dry robes, jewellery boxes, wool blankets, swim shoes and towels that are as fluffy as Muppets. They’ve thought of everything.

We change into our swim gear, and are led through a guided session with spa therapist Katie.

We’ll be running through two cycles of heat, at around eight minutes each. Once we’re in, she shows us how to breathe deeply and tapping to stimulate our vagus nerve, both relaxation techniques. Then Katie pours water on the coals and whips around a towel, to create a wall of heat, in the style of aufguss (a sauna ritual).

Usually, I’m a wimp, and I’ll go in and out constantly. I’m glad to be guided, and it makes me stick out the heat a bit longer.

When it’s nearly time to leave, she ladles ice cold loch water over our legs and down our backs.

Next, we're into the cool air, to sit on the sun loungers on the decking. Katie takes us through a guided meditation, once we’ve focused on the green hillside beyond. We listen to the sounds - a bird peeping, a fish splashing, a sheep doing its baritone vocal warm-ups - and rehydrate.

Then, back into the six-person-capacity sauna. This time, Katie will be lightly whipping us with a whisk made from oak and hawthorn leaves dipped in a bucket of water. She starts by shaking them, like she’s a cheerleader, so a rain of warm water falls on our sweaty heads, then they’re gently skimmed across our limbs.

After this cycle, we’re back outside. When Katie asks if we want another round, we say yes in unison, and we meet the stimulating whisk again.

Thanks to the structure, I feel that I’ve got more than usual out of this session. It’s certainly stimulated our appetites, and we scoff all the snacks. However, it’s a hard no to a cold plunge in the loch.

When Fraser drives us back to the hotel, he tells us about the local drovers’ roads and the history of Glen Eagles’ Clan Haldane in the area, as well as explaining why the hotel and estate’s name has the word eagles in it, when there are none in the area. Apparently, it was a linguistic corruption of the Scottish Gaelic word ‘eaglais’ for church, in reference to the local chapel to St Mungo.

We are unusually subdued in the back seat and are very happy that the day will continue to be lazy.

Just dinner in the Strathearn, with preprandial cocktails in The Century Bar. The creative drinks here are split into various Scottish landscape themes, like lochs and glens, then further divided into flavour or texture profiles. I go for Balmy (rum, fig liqueur and Aperol) and he chooses Succulent (tequila, pineapple and bergamot).

Then, we move through to the glamorous Strathearn, with its staff wearing smart uniforms that include a feathered lapel.

I order the scallop, broad beans and Alsace bacon followed by venison, while he has the lobster with angel hair pasta, cucumber and bisque, then the sirloin, all of which is as succulent as the cocktail. In lieu of dessert, we have a nightcap in The American Bar. I’ve never been in this gloriously glamorous and low-lit spot, which is halfway round the wood-panelled shopping arcade, and feels like a secret. The cocktail list is based on plants and fruits that are related to the rose.

The Smoked Cherry, with mezcal, cherry syrup and hojicha soda, is one of the best cocktails I’ve ever had. He’s blown away by Fragrant Jam (tequila, walnut, pear and chilli jam).

We recline against the purple velvet banquettes and could take root, but we’re not sure that this is what Katie meant when she told us to rehydrate.

Thus, we sensibly retire to our plush room, to dream about whisking oak leaves, hot skin, cocktails and tomorrow’s Gleneagles breakfast.

Frandy Water experiences start from £220 per 90-minute session for two, plus £80 for each additional person. Stays at Gleneagles start from £595 based on two sharing and including breakfast. For more information, visit gleneagles.com/pursuits/the-sauna-water-sports-at-frandy-water