As with so many visitors, the Blue Lagoon is my first stop. The location’s proximity to the airport (just 20 minutes, versus 45 minutes to Reykjavik) and its position at the top of so many people’s bucket list means tour buses and private transfers are lined up, ready to whisk tourists away to soak in the waters for a few hours before continuing on to their city hotels.

Outside my taxi, miles roll on with nothing but the starkness of lava fields, a black backdrop green with moss from recent rains, and like nothing I’ve ever seen before. Rounding a corner, I catch a flash of the ethereal blue water – the spillover from the nearby geothermal plant where the Blue Lagoon had its genesis in the 1970s.

Ordinarily, runoff water from Icelandic power stations sinks through the porous lava, but the high silica content in the water at this location gradually formed a layer of white deposits that created permanent pools rich in silica, algae and minerals and with an amazing milky blue colour.

That something so beautiful could be formed quite by accident seems further proof of this country’s magical character.

Initially, this spillover pool was a nuisance to the geothermal plant, but by the 1980s, locals began soaking in the waters and feeling fantastic. A doctor from Reykjavik came to explore the health benefits of the rich mineral water, and in 1992, the Blue Lagoon opened as a tourist destination – a pool holding 6 million litres of water and covering an area of 8,700sq m (94,000sq ft) with a turnover rate of 40 hours.

Soon the 35-room Silica Hotel was added, then a restaurant, an R&D centre, a skincare line and an expansion of the main lagoon.

In 2018, The Retreat at Blue Lagoon – a luxury offering including a five-star hotel, restaurant and the lagoon’s first spa – was opened. By 2019, the company’s annual revenue was estimated at €125m (US$141m, £107m), with €22m (US$25m, £19m) in profit, and close to a million visitors each year.

First impressions
I’ve seen photos of the Blue Lagoon, and it’s been on my own bucket list for years. I know it’s been named by National Geographic as one of the 25 Wonders of the World, and yet – something about the pureness of the blue waters, the contrast with the black lava fields and the sheer otherworldly beauty of the place takes my breath away.

The pools look as though they’ve been lined with a layer of white ceramic, but it’s just the silica deposits that also give the water many of its special qualities: it has deep-cleansing and purifying properties, strengthens and protects the skin, and helps it retain moisture. For those suffering from psoriasis or eczema, the water is extremely beneficial and an on-site clinic welcomes people from around the world to treat these chronic conditions. But perhaps most importantly, by a simple trick of light reflection, it’s the silica that gives the Blue Lagoon its amazing milky blue hue, as when light strikes a molecule of silica, blue is the only colour that’s reflected back.

Social spa-ing
Whatever the science behind it, the colour is incredibly inviting. From the Retreat Hotel’s lobby, floor-to-ceiling glass provides a soothing view of tranquil, steaming pools set against the mossy lava fields. The hotel has been designed to feel as though it’s part of the landscape, and inside, the minimalist decor is all wood, black stone, and chunky, earthy textures in natural materials such as wool and leather; even the heating vents have been designed to mimic the texture of lava. After a breakfast of smoked fish and avocado toast, the travel-weariness from my early-morning flight hits me, and I can’t wait to slip into the steamy water.

While I have access to the Retreat’s more private lagoons, I head for the original pool first, which is all that most day guests see. The main lagoon is 70 per cent thermal water and 30 per cent fresh, and 1.2 meters deep on average (approximately 4ft), making it the perfect depth for socialising. Day passes (ISK 5,990, US$47, €41, £35) include entrance to the main lagoon, a self-applied mud mask, and a drink from the swim-up bar (beer, wine or juices, with alcoholic drinks limited to three per wristband).

Even on a windy, drizzly morning, the lagoon is a delight; one of the first things I notice as I make my way around the pool is the sheer number of smiling faces – and not just for the obligatory selfies.

American tourists are by far in the majority, but the age range runs the gamut from 20-somethings to families to the silver-haired – and everyone looks happy. At the mask bar, dollops of silica or algae masks are handed out, and guests paint each other’s faces white or green and take photos in the steamy water.

The silica mask is said to bring strength and radiance to the skin, the algae is for reducing fine lines and wrinkles, and a mineral mask is left on to hydrate overnight – but really everyone just seems to be enjoying the tactile sensations of the mud on their hands and faces, and the way the masks and the steam transform them into something not quite themselves.

I’m struck by the jovial nature of the whole thing, and what an active kind of relaxation it is; rather than simply soaking, there are drinks to be had, masks to be applied – even a short history lecture to be listened to. This part of the lagoon is best experienced in a group, and is more fun than tranquil, though the warmth leaves you feeling relaxed and the high mineral content softens your skin and relaxes your muscles. But after a while, the number of people live vlogging got to be a bit too much for this middle-aged solo traveller, so I decided to try out the more private lagoons of the Retreat Hotel.

Privacy and tranquility
Guests of the Retreat Hotel or those booking a spa treatment have access to these smaller, newer lagoons, and the atmosphere there is decidedly different. For a start, mobile phones are prohibited in order to maintain privacy and tranquility (although staff members will head outside in fur-hooded parkas and take a photo for you, ensuring they do so out of the way of other guests).

The series of smaller, terraced pools are carved into the 800-year-old lava flow, with bridges and winding corridors making you feel pleasantly lost in the landscape. Because access is limited, I often had a pool to myself, and could float at leisure without fear of bumping into others.

A swim-up bar serves champagne from a window in the restaurant, but guests here tend to be in quiet couples rather than groups. For 79,000 ISK (US$608, €525, £450), day guests can access the Retreat Spa and pools, which includes a plush changing room with shower, a drink and access to the pools and the Blue Lagoon Ritual; at these prices, the tranquility and solitude of the pools is ensured.

For the ultimate in privacy, the Lava Cove (starting at ISK 240,000, US$1,850, €1,600, £1,370) offers a self-contained spa within the spa, including its own lagoon, fireplace and butler.

The Ritual
The pools are flanked on one side by the new 43,000sq ft (3,995sq m) spa, which includes treatment rooms for massages and facials, as well as a relaxation area where you can gaze out at the lagoons from suspended, gently swinging nest chairs. A glass-fronted sauna looks over the pools, while a steamroom set in a lava cave is warmed by natural geothermal heat and an outdoor cold well offers a brisk plunge for contrast bathing.

Within the subterranean spa is an area set aside for the new Blue Lagoon Ritual, a self-guided seven-step ritual that expands on the powerful properties of silica and algae, and is available to all spa and Retreat Hotel guests at no extra charge. Here, a desk with spa concierge serves as the starting point for the signature journey, and guests move through a series of interconnected chambers over the course of 45 minutes, where they apply a series of scrubs, masks and oils to their bodies.

In essence, the ritual is not particularly complicated, but the dimly-lit setting, and again, the sense of active participation, make for an enjoyable activity. After a mineral salt exfoliation, couples and friends slather thick white silica clay or cool green algae mud on each other, and as they wait for each to dry, they lounge in the caves and speak in hushed voices before rinsing off in geothermal water from rainfall showers. The entire process is a journey – literally, from one room to the next – but applying the layers of scrubs and masks also does the double-duty of washing away any sense of the outside world. The ritual has the effect of slowing down time while allowing guests to still be doing something, and I noticed how happy people were to be following instructions when given them – eager to move on to the next step and satisfied at the sense of accomplishment at the end.

The polar opposite of the Instagrammable story, the Ritual is instead simple spa storytelling – a chance to bring the mineral benefits front and centre.

Those who study learning modalities will tell you that engaging the senses is the best way to get people to remember anything and the dimly lit, cave-like atmosphere – heightened by the sense of sound, smell and especially touch – put people in the here and now of experience.

Highlight: The colour of the water; you’ve seen it, you know what it looks like, but nothing can quite prepare you for what it feels to be engulfed in that milky-blue water.

While floating massages have been offered for some time, the Retreat at Blue Lagoon is soon to launch a new Float Therapy, created in conjunction with Flothetta, an Icelandic company dedicated to aquatic healing. The treatment is a combination of bodywork, including stretches, pulls and light massage, along with passive floatation, and designed to transport guests to a relaxed, meditative state.

I had a chance to be one of the first to try out the new therapy, which involves wearing a Flothetta float cap and floats set just above the knees. The cap fitted snugly and clasped under my chin like a soft bike helmet, and was brilliant at keeping my head afloat without the need for a neck pillow, as I’ve experienced in other aquatic treatments. These can be obstructive as you’re moved through the water.

The 45-minute treatment (ISK 24,252, US$191, €165, £141) incorporated elements of Watsu, but as someone who’s prone to motion sickness, I appreciated the slower pace.

The treatment is offered in the same semi-private pool as the in-water massage, away from the noise of the main lagoon. I floated on my back as my therapist gently stretched and moved me as steam rose around me. As in any water therapy, there’s an intimacy and element of trust required between guest and therapist; for much of the treatment I was cradled in her arms and gently guided in a slow water dance. But in between there were pauses of peaceful, solitary floating that were incredibly powerful; watching the clouds drift across a blank sky while feeling weightless in the warm water brought me to a deeply meditative state, helped by the muffling of outside noise due to the cap – even when my ears were above water.

The treatment ended like Watsu; I was guided to an upright position against the wall for support, and my feet were planted to ground me. I felt light, free and calm, with every muscle looser, and I felt as if I’d just returned from a journey deep within myself.

Located in Kársnes Harbour, Kópavogur, is a new geothermal pool inspired by Icelandic bathing culture. The Sky Lagoon is owned by attractions and hospitality company Pursuit Collection, which also runs the FlyOver flight rides in Vancouver and Reykjavik (with new outposts slated for Las Vegas and Toronto), so it’s no wonder the whole thing has been designed as a cinematic experience that creates a lush world with amazing views.

The lagoon’s design draws inspiration from the landscapes, with an unobstructed 70-metre (230-ft) infinity pool at the centre, blurring the boundary between water and ocean. The Sky Lagoon is designed to look as if it’s been built into the volcanic landscape, but unlike the Blue Lagoon – which actually has been – the rocks have been moved here.

To reach Sky Lagoon means taking a drive 20 minutes outside Reykjavik, past bleak industrial warehouses, to the edge of the harbour. But while the journey is less than inspiring, once there, the architecture and the setting are stunning. Pursuit has gone to great lengths to create a place that feels authentically Icelandic, hiring a specialist in ancient building techniques to create a traditional turf house, with grass on the roof and a special herringbone pattern constructed from slabs of volcanic bog mud.

Sunset magic
I plan my visit for sunset, when the view over the ocean is set perfectly to enjoy the last rays of the day reflected in the North Atlantic. The menu for Sky Lagoon is simple, with just three choices: the Pure Lite Pass (ISK 6,990 US$54, €47, £41), for those short on time who only want access to the main lagoon; the Pure Pass (from ISK 9,990 US$76, €67, £58), which includes access to the Ritual; and the Sky Pass (from ISK 13,900 US$107, €94, £81), which also includes a private changing area. Pricing is variable, with weekends and sunset hours priced higher.

I opt for the Sky Pass, and the private changing area is quite quiet, with locker areas and private shower rooms. This also means I have a separate entrance into the lagoon, down a few steps and through the mouth of a cave. The approach is dramatic; steam rises from the warm geothermal water, and you wind your way past tall, canyon-like rocks before rounding the corner to see the view. It is utterly gorgeous, and well worth paying slightly more for at sunset hour.

A swim-up bar serves Prosecco and beer, and the decidedly young crowd is taking selfies through plastic-bag wrapped cell phones, chatting and generally having a sociable time. I settle into a spot on the far edge of the pool to watch the sunset – a favourite activity, no matter where I am, but utterly enchanting when floating in warm water that feels as though it’s at the end of the earth.

The Ritual
The Sky Ritual is a seven-step experience inspired by the traditions of Icelandic bathing culture and combines the healing powers of warm and cold waters, warm steam, dry heat and fresh air. Step one is to relax in the lagoon, breathing the fresh air and letting the warm geothermal water relax you. Step two is a cold plunge pool, and I’m impressed by how many people brave the icy water.

When I ask a lifeguard, he says 85 per cent of people take the plunge, another 5 per cent dip a toe in before chickening out, and 10 per cent skip it entirely. Considering the place is filled once again with American tourists who are only just now learning the power of contrast bathing, those are impressive numbers.

After the plunge pool – small, round and just enough room to dip in and out – I make my way inside for Step Three, a sauna with another stunning view across the water. Guests are encouraged to spend five to 10 minutes here, gazing through what is said to be the largest single window in Iceland, and it feels amazing after the shock of the cold water. I watch a woman set up her tripod to take images of herself in silhouette against the sunset and I must admit, she knows what she’s doing. If taking in tranquil, beautiful views is good for wellbeing, then this is the place.

After the sauna, guests are directed to Step Four, a small area with a refreshing fog mist, a light, cold spray designed to be energising for both body and mind, but not quite as shocking as the cold plunge. Once through, I’m given a small pot of Sky Lagoon’s body scrub, which I’m instructed to self-apply for Step Five, and then head to the steamroom to let it sink into my pores for Step Six, where I’m told the scrub’s hydrating benefits will be at their peak as they soak into my skin. Step Seven is a quick warm shower and a return to the thermal pool for as much relaxation time as I please.

Once again, the ritual is quite simple, but guests seem to really enjoy the direction they’re given in how to walk through the different steps, and to be actively doing something while they’re there. Groups of friends squeal in the cold fog mist, slather body scrub on each other, and laugh in the thick fog of the steamroom.

When I return to the main lagoon, I grab a glass of prosecco and enjoy the waning glow of the sunset. As the last of the light is about to go, there’s a sudden flash of green, and everyone points to the sky. “The Northern Lights?” I ask the man next to me, and he nods. The Sky Lagoon is far enough away from the glow of Reykjavik to enable this magic, and there’s a collective sigh as the mythical lights dance across the sky.

Highlight: The stunning sunset views, the incredible heritage architecture, and the number of people who braved the cold plunge!

While nothing can compare to the iconic nature and incredible colour of the Blue Lagoon – how can you go to Iceland and not see it? – the Sky Lagoon provides an entirely different experience. The Blue Lagoon is a once-in-a-lifetime experience, while the Sky Lagoon feels more like something you could do regularly on a Friday night if you lived in town. In fact, Sky Lagoon offers a Pure Multi-Pass, ISK 24,990 (US$192, €170, £145), which allows for six visits at 50 per cent off the regular price.

Both have a social spa element, with in-water bars and tactile experiences such as masks and scrubs, but the clientele at Sky Lagoon – at least at sunset – was young millennials (the minimum age at Sky Lagoon is 12, where at the Blue Lagoon children aged two-plus are welcome, making Blue Lagoon more family-friendly).

For repeat visitors or those with packed itineraries, Sky Lagoon offers a taste of Icelandic bathing traditions that’s easier to dip in and out of, as it’s closer to Reykjavik. As I told a friend who visited a few weeks after me, if you only have time for one, see the Blue Lagoon – it’s iconic, it’s otherworldly, and it stands alongside the Grand Canyon and the pyramids of Egypt as one of the 25 Wonders of the World. But really, I told him, you should experience them both.

Scores	Blue Lagoon	Sky Lagoon
Overall experience	10	9
Customer service	10	8
Facilities	9	8
F&B	9	7
Location	8	9
Total	46	41