Slipping into St Bathans’ Blue Lake is like swimming in Cleopatra’s bath – but on another planet

The colour of the lake reminds me of a film in which a group of elderly people are rejuvenated by aliens via a swimming pool

• Guardian writers and readers describe their favourite place in New Zealand’s wilderness and why it’s special to them

I grew up next to the swooshing, murky tea-coloured Waipā River in Ngāruawāhia. Always risk-averse, childhood myths of Taniwha and the idea of the snapping teeth and slither of monster eels terrified me a bit, so I never swam in rivers. Meanwhile, the promise of an unexpected brush against slimy seaweed and the thrash of the open, vast and unknowable ocean are at once beguiling yet nerve-racking to me.

Calmer than the pummel of the sea or the dark magic of rivers, lake swimming appeals. Tucked away in Central Otago is the charming historic township St Bathans, a former goldmining town now with a population of fewer than ten. A prominent feature of the town is the sublime Blue Lake which remains a breathtaking sight no matter how many times you see it. Starting in 1864, miners sluiced through the quartz rock of 120 metre high Kildare Hill.

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By 1933 at 168 metres deep, it was the deepest mining pit in the southern hemisphere. But because it was encroaching on the township, mining ceased and the pit filled with water from the surrounding hills. The lake’s stunning hue which veers from dazzling emerald to a soft turquoise is due to the mineral rich water. The surrounding white quartz tailings lend an otherworldly lunar-like appearance. Timeless, placeless and atmospheric, it looks like an alternative utopian film set from an Andrei Tarkovsy film.

Quietly spectacular, the Blue Lake is 800 metres long and 50 metres deep. Slipping into it, the silky water makes me think of Cleopatra’s bath and offers respite from the scorching hot dustiness of the summer heat. A place of extremes, the weather in St Bathans can reach searing temperatures in summer, and freezing cold in winter. Gliding through the luminous water, hemmed in by the science fiction-like tailings, I think of the music video for a 1994 David Kilgour song, the heartstopping Beached, shot around the Blue Lake and St Bathans.

In over-exposed, rinsed-out honeyed tones with Kilgour plaintively singing, “where do you come from? Where do you come from?” – it looks like it was filmed on another planet. A place steeped in rich heritage, St Bathans is a dreamy spot for heritage heads. The historic hotel built in 1882 is aptly named Vulcan Hotel and is rumoured to be haunted.

There’s a 90-minute track that loops right around the water offering sensational views of the lake and township. A shorter option of about 30 minutes offers a glimpse of the old sluicings and the goldmining machinery which converted Kildare Hill into the Blue Lake.

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With its sensuous sublimity, the Blue Lake offers swimming as a way of dreaming. It feels restorative, a word which absurdly turns my mind to those old folk in the 1985 film Cocoon in which a group of elderly people are rejuvenated by aliens via a swimming pool of water which has been charged with “life force”. In my hazy memory of the film, the colour of the lake is the same hue as the Cocoon pool, are the lake minerals revitalising? As a lifelong North Islander accustomed to subtropical lushness, the South Island with its vast landscapes, singular light quality, and spots like the Blue Lake with its esoteric eerie oddness, forever holds an alluring mystique.

• Kiran Dass is a Whanganui-based writer and reviewer who covers books, music and culture

• What’s your favourite wild place? If you would like to contribute to the series tell us about it in 200 words and send it to newzealand@theguardian.com