MY FROZEN-STIFF COMPANIONS include a monstrous fanged werewolf, a cross-eyed bare-chested butcher wielding a huge ax and the Grim Reaper lurking amid gravestones. Sweet dreams. I’m getting ready to go to sleep here entombed in snow.

Way up in northernmost Finland, I crunch in boots alone at night through the subfreezing medieval-themed SnowCastle, its cavernous glistening white hall lined with fantastical icy creatures. Earlier, bundled diners devoured lingonberry-dolloped fillet of reindeer served in steaming foil on ice tables in the castle’s 200-reindeer-fur-seat SnowRestaurant. But day visitors are all gone and the turreted frosty kingdom is now closed to the public. Making it more bone-chilling, a soundtrack still echoes: swords clink during battle, excited horses neigh, humans scream.

Surely a vodka cranberry–filled ice kuksa would stave off hypothermia, but the only “person” at the deserted ice bar is a beer mug–gripping crystal-clear knight made of ice. After he gives me the cold shoulder, I amusedly stick my beanie-clad head and gloved hands through the holes of a Middle Ages torture device chiseled from solid seas.

OK, so I’m biding time because a “mummy bag” awaits in my nippy room. Hours before, along with 15 other anxious guests, I attended the 9 p.m. safety brrrr-iefing for slumbering in the castle’s SnowHotel. Mostly I remember “it’s hard to breathe in minus 5 Celsius” (that’s 23 degrees Fahrenheit) and “keep your face covered,” which I’m pretty sure makes it even harder to breathe.

I’m on a wondrous, sometimes wacky winter adventure in Finnish Lapland, a remote Nordic region where ubiquitous reindeer outnumber people and real-life snow-globe forests bewitchingly blanket 70 percent of the terrain. Nowhere on earth can you do all that I will do here. Besides snoozing in the SnowHotel, I cruise aboard a thundering icebreaker ship and don a survival suit to exhilaratingly float among ice hunks in deathly cold seas. Moving on to the “Official Hometown of Santa Claus,” I schmooze with jolly St. Nick, get blessed by a spunky indigenous shaman smack-dab on the Arctic Circle, overnight in a Northern Lights–positioned glass igloo and pilot a runaway reindeer.

Everything is Snow

The first stop is Kemi, a welcoming 22,000-person hamlet touting “the largest snow fort in the world.” Ever since its Guinness record–nabbing debut in 1996 — its outer walls spanned more than two-thirds of a mile — the SnowCastle annually is remade with a different design, size and theme after melting each spring. Rebuilt every December entirely with ice and snow from the adjacent frozen Gulf of Bothnia, the architectural marvel looms from January to April, is kept at a frigid 23 degrees inside, and includes the SnowRestaurant, SnowHotel and SnowChapel, an ultracool venue to exchange wedding bands crafted from ice and kiss the purple-lipped bride.

Obviously, the master sculptors from Russia, China and Latvia who elaborately embellished this year’s 65,000-square-foot polar palace had a quirky sense of humor. My cave-shaped SnowHotel room is supposed to be the castle laundry.

Everything is snow, including “wet” garments drying on a rod, a washboard and tub and my bed’s playful backdrop, a life-size nobleman and mistress amorously embracing behind a curtain, just a glimpse of them sticking out. Straight across the room, a scowling old busybody peeks out her door at the groping couple (and me). Eight of the 21 hotel rooms are occupied this quiet night; I wonder who bunks alongside the snowy chambermaid giving a snowy naked princess a bath.

My ghostly breath fogs up my windowless lair as I follow bedtime instructions (a claustrophobe’s nightmare). The trick is not to wear too much because your body gets overheated and sweats. I plop on the fur-draped mattress, hurriedly peel off my puffy snowsuit and layers down to my thermal underwear, hat and socks, lie flat, wiggle into a fleece-lined body bag, then, over that sack, shimmy nose-deep into an Arctic-worthy sleeping bag and throw its hood over half my face. Gasp. My outer clothes, so they won’t crack when I put them on in the morning, are tucked between my double-zipped sleeping-bagged self and the bed. I. Can’t. Move.

I’m sure my travel mate Marilyn, who chose not to play Popsicle, is sawing logs in her thawed and heated hotel room. There is dead silence. Except for the explosive thump-thumping of my heart. Finally I slowly, calmly drift into Neverland. For much of an incredibly novel night, this ice queen sleeps like a bear.

Like a Penguin

The next day in Kemi, we do a snowmobile safari, racing across the shimmering iced Gulf of Bothnia, part of the Baltic Sea. The stark white infinity is spellbinding. When we stop, a cherry picker hoists us up to the icebreaker Sampo, a retired Finnish government ship billed as the only one of its kind in the world that takes tourists out on trips. Constructed in 1960, the powerful Sampo plowed through frozen waters to clear lanes for cargo vessels for 25 years.

Aboard the black-hulled ship, we feel its 7 million pounds of steel grind ice slabs into slush. But the highlight comes after the Sampo creates a swimming hole and brave passengers don clumsy head-to-toe rubber suits that the crew would have used in the 1960s to survive killer-cold seas if they had to abandon ship. We all hilariously resemble bright-orange Gumbys as we waddle down and slip into inky waters, the suits so buoyant we instantly float on our backs. I serenely bob among jagged blocks of ice and it is extraordinary, like being a penguin, adrift in unending pure-white frozen seas.

And then, the icing on the cake — so to speak. Around sunset, before hopping back on our snowmobiles, we catch Finland’s blue moment, a bedazzling phenomenon that envelops the glacial landscape in ethereal shades of blue.

Snow flurries swirl in the morning as we ride a train two hours to Lapland’s capital, Rovaniemi, burned to the ground by German troops during World War II and rebuilt in the shape of a reindeer head with antlers.

Dash Away

Again, we zoom off on snowmobiles, this time to find a real reindeer on a farm on the mystical Arctic Circle, where an indigenous Sami shaman named Janne leads us into a Lappish tepee. The elfin reindeer-herder wears a traditional embroidered red hat with four drooping blue points symbolizing directions of the wind.

“Are you bad? Ah, on the Arctic Circle I can take away bad spirits,” he hoots, shaking a bell-ringing rabbit-foot amulet. “Hay-lay! Hay-lay!” To kill any negative juju, he takes soot from the flaming fire pit and presses two black fingerprints on my forehead.

“We believe, in Lapland, if you come back on earth, you will come back as a reindeer.”

No thank you. I’ve seen a lot of reindeer burgers and reindeer-topped pizza on menus here.

Soon I get a quickie reindeer-driving lesson and we’re off, me grasping the reins, Marilyn praying, with antlered Esko gliding ourwooden sleigh through a gorgeous pine forest doused in virgin snow. As many as 240,000 reindeer live in Lapland — they are all semi-domesticated and owned by people — and Janne says it takes years to train one to pull a sleigh. Esko, a freethinker, stops to gnaw on tree trunks, periodically veers off trail and at the very end, goes rogue. In an apparent bolt for freedom, he darts to the side with us in tow, bangs our sleigh into the sleigh ahead and then sails us over that sleigh. I channel Santa, uttering Santa shrieks. Wanna-be Rudolph is quickly cornered.

Santa Every Day

In Santa’s official hometown, Rovaniemi, it only makes sense to sit down with the guy for a bit. I join the chatty white-bearded headliner where he meets admirers 365 days a year, next to a world map and wrapped presents in his log cabin “office” in touristed Santa Claus Village. (A Finnish radio broadcaster in 1927 first revealed that Santa lived in Lapland; since his home is a guarded secret, he opened his office here in 1985.)

“To see a little sparkle in the eyes of an 86-year-old with dementia, that’s what’s important,” Father Christmas tenderly says. He mentions that many Western children want “a new iPhone or earphone or nose phone, whatever.”

Right outside, visitors physically straddle the Arctic Circle before entering Santa Claus’ Main Post Office, an official post office handling and answering the benevolent big guy’s mail — more than 17 million letters from 198 countries since 1985. It is a heartwarming depot staffed by elves and stuffed with goodwill, such as a quarter-milelong letter from 2,110 schoolkids in Romania and a note from two Polish brothers scrawled on birch tree skin. Santa receives about a half-million letters a year, some simply addressed to “Magical Lapland.”

“It’s a very emotional place,” says head elf Katja Tervonen. “Adults write the saddest letters pouring out all their feelings about losing a job or about illness.”

On display are various gifts sent to Mr. Claus (night goggles, barber set) and hundreds of pacifiers mailed by youngsters for baby reindeer. “Children also send carrots for the reindeer but they’re not so fresh by the time they get here from Indonesia,” Katja confides.

Snowflakes on the Roof

My last night, near Rovaniemi in the powdered-sugar wilderness, I check into a balmy spacious glass igloo with a motorized bed I can position to see the famed aurora borealis (Northern Lights), said to be visible in Lapland up to 200 days a year. The igloos are on the same property as another splendid ice lodge, the Arctic SnowHotel, boasting the only “snow sauna” of its kind in the world.

This is why, wrapped in a towel, alone, inside a closet-size, snow-walled, snow-ceilinged ice chamber, I ooze puddles of sweat. The point is to ladle water onto hot rocks to engulf yourself in intense thick steam — I can’t see a thing — until an attendant pounds on the door to get you out after 15 minutes because the sauna is melting and needs to refreeze.

Jelly-legged, toxin-purged and back in the glass igloo, I entrancingly watch steady snowflakes dissolve on the see-through heated roof. Without clear skies, the “aurora alarm” in the room will not sound to wake me for a light show. But it doesn’t matter. Lapland has been a winter fairy tale. The next morning, as I wait to board a Finnair jet in Rovaniemi, I half-expect Donner and Blitzen to fly me back to California. And that might actually be a possibility: a sign overhead reads “Santa’s Official Home Airport.”