CHEPSTOW, Wales (AP) — The myths, magic and monsters of ancient Greek lore are coming to life in the BBC’s new fantasy-adventure series Atlantis — from the unlikely setting of a former frozen-food warehouse in Wales.

A vast space once stuffed with supermarket foodstuffs has been turned into a television studio, filled with sets recreating the fabled lost city, complete with temples and terracotta-roofed houses, ceremonial bull ring and regal palace.

Atlantis, which starts on BBC America on Nov. 23 is already a sizable hit in Britain, where it fills the family-viewing weekend slot previously occupied by sword-and-sorcery series Merlin.

Atlantis was created by some of the same team as Merlin, and like that show takes age-old stories and seasons them with humor, thrills and a central bromance.

Actor Mark Addy, who plays a less-than-heroic version of Hercules in Atlantis, says the recipe involves “a lot of heart and a lot of humor and a huge amount of action and adventure.”

“They wanted it to be epic in scale and in feeling, and that’s what they’ve managed to do,” he said during a break on a busy day’s filming in August.

“We’re doing stuff that you’d only ever see in movies, because it’s difficult and it’s expensive and it’s time consuming and it’s challenging,” Addy said of the 13-part series, shot over nine months in Wales and Morocco.

Atlantis opens with a young man named Jason — played by the strapping, curly haired Jack Donnelly — washing up in the city of Atlantis, disoriented but somehow instantly at home. The Oracle — there’s always an oracle — hints at big secrets to be revealed.

Jason soon meets brainy, kindly Pythagoras. “The triangle guy?” asks Jason, and indeed it is the ancient philosopher and mathematician, here a young man played by Robert Emms.

The third side of the central triangle is Hercules, in the — perhaps surprising — form of Addy, the burly actor who played a steelworker-turned-stripper in The Full Monty and King Robert Baratheon in Game of Thrones.

The casting is a sign of the show’s flexible approach to the Greek myths. This Hercules has superhuman strength, but he’s no bronzed muscleman.

“He wasn’t strong because he went to the gym, he was strong because he was Zeus’s son,” Addy explained, reasonably. “Although he was a demigod, I think he’s inherited most of his mother’s mortal traits. He drinks and gambles and he’s a womanizer.”

The cast includes Sarah Parish as scheming queen Pasiphae, Aiysha Hart as comely princess Ariadne, and Jemima Rooper as Medusa — here a young woman who has yet to become the snake-haired gorgon of legend.

But the show rests on the three main actors, referred to collectively by their fellow actors as “the boys.” For the 49-year-old Addy, being one of the boys has been fun — even if hanging out with his 27-year-old co-stars makes him feel “very old.”

He recalled nipping out for a cigarette during a meal with Emms and hearing a woman at the next table say “‘Your dad’s being very polite.’ And Rob of course didn’t disabuse her.”

Such mix-ups probably ended as soon as the first episode of Atlantis was broadcast in September. The show is watched by seven million people a week in Britain, and a second season has already been announced. And Donnelly has become something of a heartthrob.

On set in August, Donnelly said the feeling that his life was about to change was “amazing and daunting.”

“It’s the best thing that’s ever happened to me by a long, long way,” said the cheerful actor, looking as bouncily indestructible as his character, who is required to battle bulls, baddies and Minotaurs on a weekly basis, clad in a fetching jerkin.

“The first few weeks I was terrified. I was just waiting to get fired. … I mean, my last job before this was in (comedy show) ‘Misfits’ and I was wearing a white rabbit mask and I had no lines and no one saw my face.

“To go from that to this, I suddenly thought ‘I’m not ready.’ It has got slightly easier since then.”

Emms has a longer CV, including major film roles in War Horse and opposite Julia Roberts in Mirror Mirror. But he said he was also nervous — although that was offset by his family’s delight at his new role.

“I’ve played … some not very nice people, some weirdos,” he said. “And my mum’s like, ‘I’m so pleased you’re playing a nice person who doesn’t kill anyone.’ She always just wanted me to play a doctor.”