Eagle-eyed Gwynedd viewers of Sky original show, Under Salt Marsh, will spot some familiar sights as part of the series was filmed in Fairbourne, Barmouth and Llanbedr.

Filming took place at Fairbourne Golf Club, Llewelyn Drive, Friog Corner, Beach Road and its seafront and sea wall, as well as at Barmouth Estuary, the field at Borthwnog Hall near Bontddu, the Mawddach Estuary and Sylfaen Farm, Panorama Road, Barmouth.

Shell Island at Llanbedr - the quay, causeway and marsh - were also used. Posting on Facebook, Shell Island said: “The cat is out of the bag, the filming locations have been named! From all of us at Shell Island, we cannot wait to see how it's turned out, and no, we will not be giving away any plots!

“But from what we saw and heard during filming, its going to have everyone on the edge of their seats each episode!”

The fictional Welsh town of Morfa Halen is a tight knit community precariously nestled between towering mountains and a fast-encroaching sea that threatens its very existence.

As a once-in-a-generation storm threatens to strike the town, former detective turned teacher Jackie Ellis (Kelly Reilly) discovers the body of her 9-year-old pupil, Cefin. The discovery sends shockwaves through the community, reviving the ghost of an unsolved cold case that rocked the town three years prior - the disappearance of Jackie’s niece, Nessa, which cost her career and broke down her relationship with her sister.

Cefin’s death summons Jackie’s former partner, Detective Eric Bull (Rafe Spall), back to Morfa Halen to lead the investigation into a community he failed once before. With the looming potential that the cases are linked, Jackie and Bull must reconcile and race to uncover long-buried secrets inside Morfa, before the storm breaks and all the evidence is gone for good.

Creator Claire Oakley said: “Most of my work has been inspired by place and with the UK’s landmass decreasing due to coastal erosion and sea level rise, I felt inspired to set a story in a colourful coastal community, full of spirit, that we want to see saved.

“I’ve always been interested in psychogeography: how the landscape can have a psychological effect on its characters and vice versa and I felt that a precarious position on a salt marsh could provide a rich psychological landscape to delve into.

“As I started to imagine the show off the page, the natural environment felt like it was of the upmost importance. It wasn’t just a backdrop but an integral part of the story.

“I’ve spent a lot of time in North Wales over the last 10 years, walking, photographing the landscapes, visiting out of the way places; it’s very close to my heart. I felt we could photograph the landscapes in thrilling and atmospheric ways, juxtaposing the remote natural beauty against the precariousness and eccentricities of human life. It was perfect for the story and so our journey began.”

There are six episodes in Under Salt Marsh. The first two premiered on 30 January on Sky and NOW. The remaining four will be added weekly on Fridays.