'Belfast adopted me when making How to Train Your Dragon' - Gerard Butler

He plays the role of Viking leader Stoick, in the Dean DeBlois-directed story of a conflict between dragons and Vikings on the fictional isle of Berk.

The real-life locations that make up Berk in the film are in Belfast, Dunseverick Castle on the north Antrim coast and Tollymore Forest in County Down.

Speaking of his time living in Belfast, Gerard Butler described the locals as "his people".

"There's not much of a difference whether you're in Glasgow or if you're in Belfast," he added.

"I felt like they felt like I was their son.

"Everybody just kind of adopts you, it was great, I loved being there."

The production spent several months filming at Belfast Harbour Studios and Titanic Studios.

"These sets are some of the best ever built," he said.

"And that was the Northern Irish crew and they did a great job. That wasn't easy to do.

"Because when you watch these animated films, you say how [are] you ever making this? How [are] you going to pull this off.

"And we did it."

The Scottish actor, who was born in Paisley, said he loved filming in Northern Ireland and was well used to the cold temperatures - when he wasn't wearing his huge costume.

"I say it was cold, [but] I was cold when I wasn't working. When I was working, I was hot.

"Everyone else was cold, but I had seven layers on. That costume was really heavy. I wore that for nine weeks.

"When I'd everything on, it was 90 lbs.

"It was intense, but it also meant I could fully transform into Stoick - I felt like when I stepped onto that set, I've got that helmet, I'm like eight feet tall, like 'I'm here, it's hard not to notice'."

Away from the set, Butler caused quite a stir when spotted out and about in Belfast and nearby towns.

He said it could "get a bit crazy" at times, with fans keen to say hello.

On one occasion, he thought one bar, described as "an old man's pub", would be "cool" with him and create no fuss.

"I walked in and there were three different people who recognised me.

"And I'm saying hello to them.

"The whole bar started moving our way, it was late at night, everyone was drunk.

"These guys said to us, we'll help you and they kind of pushed us back out the door - basically because it got so crazy in there.

"I had said to my manager before, this one's good, this is an old's man's pub. They'll be cool… then barged back out the door, like OK, OK maybe not tonight," he added, laughing at the memory.

Speaking about the film's sequel, he said he was "sure it will happen in Northern Ireland".

"I can't imagine it happening anywhere else. I know Dean [DeBlois] our director loved it there, loved the crew, everybody did.

"The people worked really hard. It's a lot of work to make these movies. This one was huge. So people there did a great job. He was over the moon with the whole crew. So I can't imagine it going anywhere else."

Meanwhile Butler's castmate Nick Frost also proclaimed his love of the city.

"It's full of history, it's beautiful and I got to see the H&W cranes," the Shaun of the Dead star said.

"As a bit of an engineering fan, I loved that they were right where we shot. It's incredible. Love it."

As for returning to Northern Ireland to shoot a sequel, Frost admitted he had another preference.

"I'd like them to shoot in my house or in the garden, if they could build a little set somewhere near my house."

Referring to the types of dragon featured in the movie, he added: "I could probably fit a Terrible Terror, but I couldn't fit a Night Fury."

The young stars of the film - Mason Thames who plays Hiccup and Nico Parker who plays Astrid - said it would be a joy to film "whereever it is".

"Northern Ireland would obviously be amazing because it would be like a big reunion," Thames said.

"I think we'll go back there regardless."

The pair described the filming conditions as "freezing on the north coast", but "gorgeous".

They admitted their love for the Northern Irish accent, and also revealed a case of food poisoning that afflicted the entire crew - except, that is, for Mason Thames who said he escaped the bug thanks to his first attempt at cold-water swimming.

Given the temperatures however, he said it was an activity he wouldn't be trying again.