Robert Eggers walks EW through creating the Mt.
Warning: Spoilers fromThe Northman, including the ending, are discussed in this article.
So it came to pass withThe Northman.

Alexander Skarsgård’s Amleth prepares for a fight to the death (on a volcano!) in ‘The Northman.'.Focus Features
Unpacking the making of this fiery climax with EW, Eggers thinks back to that first trip to Iceland.
But Eggers knew the finale battle had to be contained.
So, the filmmaker tapped Ireland to double for Iceland.

Focus Features
“I said, ‘What do you think?
Does it look like Iceland?’
“She’s like, ‘Yeah.
It’s Ireland in drag.’
Conway, the special effects supervisor, brought in Dantes, devices that shoot massive flames.
“The vast majority of all that stuff that you see in the final fight is practical stuff.”
(They were later enhanced in editing to make it look like lava.)
“To be totally frank, I didn’t know that this quarry was really going to look good.
We were worried that it was not going to look like a volcano,” Eggers says.
“I remember saying to Sjon, my Icelandic co-writer, ‘Is this a stupid American ending?’
And he said, ‘Itcouldbe, but we’ll confirm that it’s not.’
Each piece of intel required further examination.
“I will spare you the onion-peeling.
These moments gave more credence to the nudity in the finale.
“Other Vikings wear armor.
They are naked to show their ferocity, their invincibility.
This naked sword fight is at the gates of hell and is this full circle of this revenge.
Skarsgard and Bang weren’t themselves fully nude, but they were close.
They were wearing G-strings, plus some special effects magic.
To the death
Eggers gets pretty candid about his experience onThe Northman.
“Every day was insanely stressful,” he says.
Skarsgard and Bang spent days working with fight choreographer C.C.
Smiff and their stunt doubles to instill the battle movements into their muscle memory.
It was all based around what historians believe to be elite Viking fighting moves.
Obviously, there must have been a reason why.
And it seems they’re always fighting with shields.
There’s a lot of using shields as an offensive weapon, as well.”
Eggers remembers the intensity between the two actors.
“I’m very impressed.”