Revelling in a spa for a day, your way, is magic, writes Petrina Darrah

There's an element of the fairy tale about Maruia Hot Springs. Something about driving the narrow Lewis Pass road, following twists and turns through the dark beech forest until the isolated thermal pools suddenly appear out of the mist. Or maybe it's simply the mystical appeal of swapping the frenetic pace of everyday life for immersion in healing mountain waters and deep relaxation. Either way, heading there on a solo day retreat feels magical.

Travelling alone means shameless self-indulgence. I can follow my whims and spend each day exactly how I like it. This is exactly how I make the spontaneous decision to take myself on a Maruia Hot Springs retreat. On an extended long weekend in the South Island, I head to Kaikōura to climb Mount Fyffe, then decide that a day spent in a mountain spring is the best way to rehab my legs.

As I make this decision the night before, all of the Maruia's glamping options - riverside bothies that look wonderfully cosy - are fully booked. I choose the day retreat option instead. At $75, the day spa package includes delights such as home-brewed kombucha on arrival, access to the guest-only relaxation lounges replete with soothing music and open fireplaces, yoga classes, sauna treatments, and crucially, a robe and towel. I had flown carry-on only, so having a real towel, and not my scrap of lightweight fabric, is one of the most alluring prospects.

At Maruia Hot Springs, the location is as much a tonic as the waters themselves. Cut off from mobile reception and kilometres from the nearest town, the spa has a zen-like atmosphere that offers the great luxury of time uninterrupted. No obligations, no notifications, no pressure to be anywhere or do anything other than relax.

It's a spot that's been luring travellers for more than a century. What started out as a cluster of rustic huts at the end of the 1800s morphed into chalets and a hotel after the World Wars, as the mineral waters gained popularity as a healing treatment. Eventually, the hotel became a pub, added a gas station, and then transformed again into a traditional Japanese Onsen in the late 1900s.

The constant in all of this was the water. Infused with the potency of dissolved minerals from below the Earth's surface, the springs are tinted an unusual deep green. Suspended in the water is unique black algae, a slippery substance with purported health benefits.

The steep valley walls of Lewis Pass are cloaked in dark beech forest and mist, with glimpses of snow-dusted alpine tops briefly visible in between whorls of white cloud. Bathing in the emerald pools exposed to the chill alpine air, gazing down the river valley into passing sweeps of rain, is incredibly meditative.

For most of the day, I drift between the pools, the steam room, and the lounges in the main building, swaddled in my fluffy robe and a pleasant state of languor. I had packed a book and even my laptop in case I became bored, but once every muscle had been dissolved to toffee by the hot water, all I want to do is stare at the passing rain and gently undulating treetops in a spaced-out way. No wonder some people get unnerved by wellness retreats.

I book myself into the "signature sauna experience", which I am assured cannot be missed. The mountain sauna is wooden lined with an impressive view of the valley. The heat pumping from the hot rocks is generated from electricity produced by the resort's own hydropower generator.

Our sauna experience is led by a local Ngāi Tahu bloke in shorts and a bucket hat. He pours water infused with clove essential oil over the scorching rocks and spins a towel to fan the sauna guests as he regales us with stories from the area. He describes how pounamu traders used to stop off at the hot springs to bathe their weary limbs, as they hauled the stone from the West Coast through the mountainous pass. The healing waters of these hot springs also drew warriors as a place to heal their battle wounds and rest in comfort.

After 15 minutes of sweltering, he leads our group outside and encourages us all to jump in the plunge pool, round and deep as a well, with fresh river water burbling up inside. Plunging into freezing cold mountain water seems like it would be a terrible idea. But after one dip, I'm hooked. It's exhilarating.

I can't get too much of the water, both hot and cold, so it's not until the snow clouds drop lower and darkness creeps in, that I finally drag myself out of the hot pools and surrender to my robe. Walking outside into the cool evening air, I feel both relaxed and invigorated. Nourished. I think I could get used to day retreats.

CHECKLIST: MARUIA HOT SPRINGS

DETAILSMaruia Hot Springs is located on Highway 7 in the Lewis Pass National Park, 2hr 30min drive from Christchurch Airport. The natural hot springs, day spa and wellness retreat is open five days a week, Thursdays to Tuesdays
maruiahotsprings.nz

Six great natural hot springs for self-care spa days

The Lost Spring, Whitianga

With geothermal pools, a day spa and relaxed restaurant, The Lost Spring is a hidden gem in the Coromandel's popular beachside town of Whitianga. The mineral water springs travel from more than 660m below ground, up through fossilised rock dating back more than 16,000 years, emerging in pools surrounded by native bush. Water temperatures range from 30C to 41C, and poolside service is available so you can enjoy drinks and platters while you soak. Open Friday-Saturday, 9.30am-9pm and Sundays, 9.30am-7pm, you can choose from 90 minute or four-hour reservations.
Massages, facials, reflexology and manicures/pedicures are on offer at the onsite Treetop Day Spa, open Thursdays-Sundays, 9.30am-7pm.
thelostspring.co.nz

Te Aroha Mineral Spas, Te Aroha

In the domain at the bottom of Mt Aroha, these natural hot springs have been soothing visitors since the 1800s. You'll need to visit with a friend - there is a minimum of two adults per spa - but there's plenty of room for both of you to unwind in the spacious wooden tubs. Temperature controls mean you can choose the perfect heat for you. Each spa comes with its own private changing area and en suite bathroom, and if you're looking to dial up the romance, there are special packages available including candles, drinks, chocolates and flowers. Massages and beauty treatments are also available. tearohamineralspas.co.nz

Polynesian Spa, Rotorua

One of the country's most famous hot springs complexes, Polynesian Spa is billed as "New Zealand's original geothermal bathing experience". Visitors have access to a range of 28 mineral hot pools, sourced from two natural springs - one slightly acidic to help relieve tired muscles, aches and pains, one more alkaline to nourish skin. Public, private and family pools are available, along with a range of retreat day spa packages, including geothermal mud treatments. polynesianspa.co.nz

Wairakei Terraces, Taupō

This site just outside Taupō has been soothing visitors for hundreds of years, thanks to its mineral-rich waters and idyllic setting. Mineral water is geothermally heated 1.5km underground, then emerges in a manmade geyser before flowing down silica terraces, ending up in three outdoor pools of striking blue water. In between soaks, take a walk around the terraces to get up close to the geyser and see intricate carvings representing te ao Māori (the Māori world) and local iwi Ngāti Tūwharetoa. Massages, reflexology and facials are also available. wairakeiterraces.co.nz

Hanmer Springs, Canterbury

About 90 minutes' drive from Christchurch, this impressive complex has 22 mineral pools to choose from, along with sauna and steam rooms, hydroslides, a lazy river, and freshwater pools for swimming or playing. It's a family-friendly venue, so if you're hoping for some solitude and silence, book a private pool for a well-deserved soak. If you're happy to share, outdoors you'll find aqua therapy, cascade, rock, rainbow, hexagonal and sulphur pools, nestled in native bush and with alpine views. The Spa at Hanmer Springs is next to the pools, with massage, facials and beauty treatments available. hanmersprings.co.nz

Tekapo Springs, Mackenzie

At the base of Mt John looking out across the milky blue waters of Lake Tekapo, this family-friendly complex offers a range of options for relaxing soaks, including three hot pools, an aqua play area, two cooler pools, steam and sauna rooms, a cold plunge pool and the Glacial Day Spa. In winter there's an outdoor skating rink and snow tube ride; in summer there's a 150m downhill waterslide. Situated in the Aoraki Mackenzie International Dark Sky Reserve, there's also a night-time stargazing experience on offer, combining a guided stargazing and then by a soak under the night skies while you lie on a floating hammock. tekaposprings.co.nz

This piece originally appeared in New Zealand Herald Travel here.