The production also used Glasgow Cathedral, although it was almost dismissed as a location.
"We looked in the main space and although it was magnificent, it was just too big for the intimate confessional scene we wanted to shoot," Tamara says.
"The arches were all too high. You had no sense of the scale of the place. And then I realised Outlander had shot scenes in the lower chapel where the Gothic arches are much closer to the ground.
"We'd missed that and as soon as I told Guillermo, we knew it's what we needed for the scene."
Tamara credits these places with inspiring the director to create new scenes and build the story around what they found.
But Scotland's darker characteristics made their way into the film even when they weren't filming.
The production team absorbed the spooky atmosphere of the places they stayed, such as Norwood Hall Hotel in Aberdeen.
It was bought by a James Ogston in 1872 and rebuilt in 1881 to house his lover. Today, Ogston apparently haunts the dining room, his lover is said to walk the main staircase and his wife has been seen in bedroom nine.
Del Toro wrote on social media that his colleague had witnessed strange electrical and physical phenomena inside room nine and the director had snapped up the chance to stay in the haunted bed chamber.
They swapped rooms but the stay was - sadly - uneventful in paranormal terms.
Still, Tamara left Scotland convinced it's a country full of ghosts and the gothic.
"Scotland is so old. It is haunted. In Edinburgh, I would get up at six in the morning before the tourists hit the Royal Mile.
"And after a rainstorm, I would see the sun coming up at the end of the Royal Mile and licking across these wet cobblestones.
"And I was like I was back in the 18th century."
Frankenstein is on limited release in cinemas around the country and will be on Netflix from Friday 7 November.