TOSSED between clawing waves with only a wooden oar and magician’s top hat, Moominpappa embarks on a whimsical journey to find a distant lighthouse.

It’s 34 years since I read the story of a snouty patriarch who frolics with seahorses and befriends The Groke, a desperately lonely figure scarred with a permanent scowl, who turns ground to ice wherever she treads.

But I do recall a handwritten inscription in my copy of Moominpappa At Sea, promising the Moomins would take me on a special adventure one day.

Now I’m standing in front of a first edition illustrated book sleeve, part of a 2,000-strong collection of drawings, triptychs and related paraphernalia on rotated display at the world’s only Moomin Museum, which recently opened in Tampere, a two-hour train ride north from Helsinki.

Since Finnish artist, sculptor and illustrator Tove Jansson published her first book in 1945, the magical Moominvalley has become a worldwide cult phenomenon; children are drawn to the playful, fanciful characters, while the droll humour and philosophical allegories resonate with an older audience.

Jansson’s Moomin work was donated to the Tampere Art Museum in 1986, after Helsinki City Museum declined the collection on the basis it wasn’t “proper art”. A temporary exhibition of 100 pieces in the Tampere gallery’s basement lasted for three decades, until structural damage resulted in an evacuation three years ago.

Moomin Museum Director Taina Myllyharju was given an “almost unlimited” budget to employ the best architects, artists and designers in her quest for creating a new space in the park-fringed Tampere Hall.

A reading library stocks the 12 Moomin books in multiple languages, and a shop sells themed postcards and stamps (conveniently, there’s a postbox on site) and exclusive merchandise given the seal of approval by Tove’s niece, Sophia Jansson.

Restoring the works, particularly the detailed triptychs Jansson worked on with her life partner, graphic artist Tuulikki Pietila, was a painstaking business. Often, the women would use anything they could find lying around in the summer cottage they shared on remote island Klovharu. These colourful 3D scenes were ephemeral snatches of imagination; they weren’t designed to last.

Crossing a wasteland on spindly, insect-leg stilts, Moomintroll and Sniff stare up at a cobweb-shrouded model schooner. The Jansson family heirloom forms the centrepiece of a tableau from the apocalyptic Comet in Moominland, which critics have linked to post-war gloom and the looming spectre of nuclear attacks.

And in another carefully crafted model, pieces of Pietila’s and Jansson’s own jewellery festoon a winter scene where Christmas is a fearful creature who must be appeased with a fir tree.

I get the impression that with every seashell collected and each piece of Styrofoam painted and glued, the two artists climbed further into their fantasy world and the act of doing became a form of escapism.

Students from the game design section of Tampere’s College of Art took 3D scans of Jansson’s 43 tableaux to create a giant Moomin house, an exhibition highlight, and Myllyharju hints that in future the data could be sent overseas to construct replicas for exhibitions.

As for the delicate charcoal, pen and watercolour drawings, they will never go on loan again, she insists, and lights are kept permanently dimmed in the two-storey exhibition space to safeguard their preservation.

Under the cover of darkness, I comfortably sink into the Moomin’s make-believe world, with the help of several interactive displays; inside a cavernous top hat, a projector bestows my shadow with loppy Sniff ears, and by waving my hands, I can throw bolts of lightning above a mural of ghostly, wide-eyed Hattifatteners.

From fireball comets hurtling towards earth, to belligerent waves threatening to swallow the sky, Jansson was fascinated by the forces of nature.

On her birthday, August 9, which will also mark the museum’s official opening, she would swim in the sea with a crown of plaited flowers around her head.

So it’s fitting Tampere is a city connected to wilderness. Two giant lakes sitting at different elevations create a source of hydroelectric power which has shaped the industrial, red-brick ‘Manchester of Finland’. But the environment is still respected.

Heidi Savolainen from Adventure Apes introduces me to the region’s sauna culture, on a trip to Rauhaniemi, set on the birch tree-lined shores of Lake Nasijarvi.

“There is always room for one,” she declares as we squeeze our pefletti (wooden sauna seats) into a narrow room heaving with sweaty flesh and plumes of steam.

After 20 minutes spent boiling my blood, I step outside and climb down a set of metal stairs into the crisp, satin-soft lake, where the stinging shock of cold water becomes perversely addictive. Afterwards, I follow a path into the forest, picking plump blueberries and fan-leafed wood sorrel so sharp it leaves me grimacing like The Groke.

The herb appears on my dinner plate that evening, as part of six-course taster menu at restaurant C. Ilka Isotalo and his team take pride in using ingredients sourced from a maximum 50km radius; only wine, tea, coffee, salt and pepper travel from further afield.

Although Jansson spent much of her time on Klovharu and visited Tampere, she lived, worked and died in Helsinki. Throughout her life, she was desperate to be taken seriously as an artist and several of her murals are on display at the Helsinki Art Museum (HAM).

In Electricity, a piece commissioned for the Pitajanmaki factory of the Stromberg company, luminous lightning veins strike just like they do above Moominvalley, and in the fresco Party In The City, a small Moomintroll hides in the left-hand corner.

In fact, the fairy-tale creatures can be found all over the capital; since December 2016, five themed Mumin Kaffes have opened, with play areas, plush toys and peaceful surroundings.

Next month, fashion label Chinti & Parker will launch a range of limited edition Moomin cashmere jumpers, and in October London’s Dulwich Picture Gallery will host the first major UK retrospective of Tove Jansson’s work.

Clearly, Moominpappa’s humble ship is setting sail for world domination, and we’re all invited to jump on board. Several decades on from my first encounter with the adorable flumpy characters, it’s an adventure I’m happy to embrace.

GETTING THERE:

Finnair (www.finnair.com; 020 80 01 01 01) flies from London Heathrow, Manchester and Edinburgh to Helsinki with return fares starting from £155.

Stay at Solo Sokos Hotel Torni in Tampere from £127 (142 euro) per night.

Visit the Moomin Museum (www.muumimuseo.fi/en/) for £11 (12 euro) per adult or £5 (6 euro) per child.

A guided swimming and sauna tour with Adventure Apes (www.adventureapes.fi) costs £44 (49 euro) per person.

A six-course menu at restaurant C costs £61 (68 euro).

For more information on Finland, see www.visitfinland.com