While Jackie Ellis (Kelly Reilly) and DS Bull (Rafe Spall) search for answers in Under Salt Marsh, there’s one quiet but essential character playing its own part in the unfolding tale – and that’s Wales itself.

Various parts of the North Wales coastline were used as inspiration for the fictional town of Morfa Halen. Nestled where the mountains meet the sea, and reached by a causeway across vast marshlands, Morfa Halen is a community bound by nature and fractured by an unimaginable crime. As an investigation takes hold of the town, a once-in-a-generation storm begins to gather out to sea and threatens to wash all the evidence away.

Now officially the biggest original drama launch since The Day of the Jackal, the team behind Under Salt Marsh open up on how the Welsh culture and landscape became an essential part in bringing the show to life.

Under Salt Marsh creator Claire Oakley was inspired by the North Wales coastline and environment as she began to shape her tale.

“It wasn’t just a backdrop but an integral part of the story,” she said. “I’ve spent a lot of time in North Wales over the last ten years, walking the mountains, photographing the landscapes, visiting out of the way places and 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.”

Claire partnered with Little Door, a Cardiff based independent production company, to help realise those surroundings on screen. In a painstaking collaborative effort, Elwen Rowlands – CEO of Little Door and executive producer for Under Salt Marsh – headed a team of scouts to find the perfect location for Morfa Halen.

“We worked with scouts who hadn’t filmed in that region before, so they brought fresh eyes. We wanted epic landscapes to make the community feel small against the wild beauty,” she explained.

Under Salt Marsh, under the watchful eye of Oakley and Rowlands, was shot on location across North and South Wales, while other elements of the show, including the wooden huts that house the community of Spider Island, were built and shot in-studio at Dragon Studios – based just outside Cardiff – so they could film safely.

Key locations used include Mawddach Estuary, Newborough and Aberffraw in Anglesey, Fairbourne in Gwynedd – surrounded by Snowdonia National Park and Shell Island.

Adam Scarth, Director of Photography on the production of the series, said: “Shooting in Wales was an incredible opportunity. The authenticity comes from responding to the landscape and the performances.

“The scale of the environment was vital — it adds a mythic quality to the story, making you believe something monstrous could hide in those woods.”

The production team employed hundreds of crew across North and South Wales, supporting local jobs, skills development and training as part of their bid to increase long-term industry investment.

As well as the hundreds of crew members from Wales, Under Salt Marsh also cast a number of Welsh actors – all of whom shared their love of being able to shoot there.

Above all, it was the sense of the community the cast took pride in the most – with Kimberley Nixon, who plays Cefin’s mother Shell, and Jonathan Pryce, who plays area patriarch Solomon, celebrating the united spirit that comes with being part of a Welsh team.

“Welsh crews have a special magic,” said Nixon. “There’s camaraderie, support, and a kind of unspoken understanding. It’s like having a backbone of home behind you.”

“There’s a much stronger sense of resilience in the community now compared to when I grew up in North Wales,” added Pryce, who noted the production offered him a chance to reconnect with his roots.

“Back then, life was calmer and community meant coming together for local events like Bonfire Night or the village fete, but there wasn’t much activism.

“Today, being Welsh — especially Welsh-speaking — feels more prominent, and I regret not keeping up my language skills. It’s good to see the community represented so strongly, as it can serve as a rallying cry for others across Wales.”

The Welsh language features heavily in the series, with Nixon noting: “The North Walian accent, the subtle use of Welsh language — it’s not performative, it’s just real. It reflects how people actually live and speak, and the way the Bevans use Welsh to their advantage adds even more to the plot.”

 Above all, the production aimed for authenticity. Steve Herbert, production designer on Under Salt Marsh explains “We cherry-picked elements from real places and built a town that felt authentic but also served the story,” he said. “The salt marshes, the skies, the mountains — they gave us the natural drama we needed.

“Morfa Halen became a small, special pocket of the world, a place that feels timeless and deeply rooted, which makes its vulnerability all the more poignant.”

It was important for both Sky and Little Door to also practice what they preach when it came to environmental impact – especially considering so much of the story is based around the cusp of an ecological disaster.

Designed as a sustainability-first production, Sky invested in additional sustainability funding to enable initiatives beyond standard production practice. The production also operated a fully electric unit car fleet, with departments largely using electric vehicles throughout.

The production worked with local ecologists and Natural Resources Wales to protect biodiversity, including saltmarsh environments, with a WWF x Sky educational event being held for cast and crew, focusing on saltmarsh conservation and environmental protection.

It is the team’s hope that, through infrastructure investment and sustainable production practices, they’ve set a bar for future productions within the area to match and benefit from.