LARGER than an igloo and just as solid, The Groke appears lost in her own icy thoughts. Gaze fixed on an empty space, Tove Jansson’s lumpy, lonely and largely misunderstood character bares her trademark grimace and, in keeping with the cult Moomin books, she’s literally frozen to the spot.

Expertly sculpted from eight blocks of Lapland’s finest ice, the mysterious creature is part of an ambitious new ice cave exhibit at the Vesileppis Resort in Leppavirta, a small town in Finland’s central Lakeland region. Inspired by Moominland Midwinter, Jansson’s fifth Moomin book, the attraction features 16 tableaux, set amid snow scenes and slides, all chilled at minus four degrees Celsius, 30 metres below the hotel.

It cost almost 30,000 euros to transport and store blocks harvested from the Lainio and Puruvesi rivers, where currents slow the icing process, leaving it clear and bubble-free. Anne Lantto from the resort’s marketing department justifies the the expense by declaring: “Moomins deserve the best.”

Anne, like thousands of other Finns, is a dedicated fan of the Moomins, a family of flumpy, wide-eyed creatures resembling two-legged, albino hippos, whose sense of adventure appeal to a cross-section of generations.

Born from childhood stories of ghouls guarding candy cupboards, Moomintroll became artist and author Tove Jansson’s alter-ego, later starring in nine illustrated story books, published between 1945 and 1970.

The inhabitants of Moominvalley first found international fame in the 1950s, and their appeal has only continued to grow. In March, Japan plans to open a theme park in the city of Hanno, and around the same time, a new animated TV series will be broadcast in the UK through Sky Original.

I’m in Finland for the programme’s premiere, attended by British voice stars Jennifer Saunders, Rosamund Pike and Taron Egerton, so after a short but blissfully crisp-blue stay in Lakeland, I board a six-hour train south from Kuopio to capital city, Helsinki.

A fan of the Moomins since childhood, when I was given a book with a note promising me a visit to Moominvalley one day, I’ve loved them even more as an adult. Beyond the charming illustrations and poetic storytelling, it’s the sentiments they evoke; from flower-strewn forests to rough seas and misty winter suns, the landscapes are distinctly Nordic, reflecting a love of nature, even in its darkest forms.

Outside the train window, a labyrinth of lakes now forms a skate rink looping clusters of pine forest, branches buckling under the weight of fresh snow. Around 74 per cent of Finland is covered by trees, making it the most densely forested country in Europe, and dressed in winter whites, their regimented spines are fleshed out with all sorts of monstrous, amorphous limbs.

“Some of my favourite book covers are of landscapes,” says Moomin expert and author Sirke Happonen, who has even penned academic papers on the subject. Over dinner later that evening at Elite restaurant, an elegant 1930s-style salon once frequented by Tove Jansson, she shows me a collection of first editions, neatly packed into her canvas knapsack.

“Tove loved nature and flowers, and these often appeared in her illustrations,” she explains, showing me a drawing of a horse smothered in colourful petals.

Achieving the correct tones and hues was vital to the new Gutsy Animations series, modernised to compete with the likes of Pixar, while retaining the humour and thoughtfulness of Jansson’s original books. I watch an episode at Moominvalley’s black-tie premiere at the Valkoinen Sali hall, sipping raspberry cocktails from Arabia’s collectable Moomin mugs and eating Moominmamma’s favourite pancakes with whipped cream and jam.

Rosamund Pike, who voices the matriarch and is a fan of the characters, had a Moomin manicure especially for the event, and stayed on in the city to celebrate her 40th birthday. Afterwards, I even hear her publicist request a collection of mugs to be wrapped up and taken home.

She’s not alone. Every Finn I speak to reminisces about the limited-edition crockery they’ve collected since childhood, even refusing to drink from some rare pieces, which can sell for several hundred euros on eBay.

Although fiercely monitored by family firm Moomin Characters, whose authorisation was essential for the Vesileppis ice cave and the Gutsy Animations series, Moomin memorabilia is everywhere: Snorkmaidens decorate tea towels, Snufkins function as cookie cutters, and the ghostly, electrically-charged Hattifatteners masquerade as table lamps.

But Sophia Jansson, Tove’s niece and the creative director of Moomin Characters, admits a saturation of consumer products is a concern - particularly in a climate where sustainability is such a hot topic.

“Excuse my language, but the last thing I want is s**tloads of plastic stuff swimming around in our oceans,” she fumes when we meet at Tove Jansson’s atelier at Ullanlinnankatu 1, in the centre of Helsinki. Although she does recognise the need to revamp and reinvent.

“Classics will not always be classics,” she laments. “People will forget, and the stories will gather dust. You have to keep a brand alive.”

The idea of a brand does seem at odds with Tove Jansson, who recoiled from the hoopla and lived a largely Moomin-free life from the 1970s until she died on June 27, 2001. Her atelier bears little reference to the creatures; instead, the mezzanine studio is filled with books and the abstract artworks with which she was desperate to find fame.

Although the perfectly intact studio is not accessible to the public, fans of the Moomins can find many of Jansson’s original illustrations at the Moomin Museum in Tampere, a two-hour train ride north. Opened in 2017, the beautifully attired space features around 2,000 pieces donated by the artist to Tampere Art Museum, after Helsinki foolishly rejected her offer.

Minna Honkasalo, a researcher at Tampere Art Museum, points out one of her favourite drawings from Moominland Midwinter, featuring the young protagonist and Too-Ticky (a character inspired by Jansson’s life partner Tuulikki Pietila) sat around a ‘snow lantern’.

“This is something very Finnish,” she coos. “To build a tower of snowballs and put a candle inside.”

After my tour, I join a graphic workshop in the museum’s Moomin Studio, learning a scratchboard technique used by Jansson to achieve her atmospheric, wintery scenes. My thoughts turn to The Groke, that lamentable, pity-inducing great lump for whom I’ve developed an affinity, and the frozen sun, which disintegrates into a crystalline haze at this time of year.

Although my own efforts aren’t a patch on Jansson’s masterpieces, they do give me an appreciation for her talent and her passion for the place she called home. Melancholic shadows and mysterious landscapes make me want to climb right into her pictures and row boats to forgotten lighthouses, or make my own snow lanterns beneath a frosty canopy of trees.

Finally, I’ve been granted my trip to Moominvalley, a destination you’ll never find on a map, because in Finland, it’s everywhere you go.

GETTING THERE

Finnair (finnair.com; 020 8001 0101) flies from London Heathrow, Manchester and Edinburgh to Helsinki, with return fares from £107 in Economy Class, including all taxes and charges.

For more information on the destination, go to visitfinland.com.

For information on the ice cave, visit icecave.fi.

For more information on the Moomin Museum, visit muumimuseo.fi/en.