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.

Home to the fictional town of Morfa Halen, the Welsh coast was used by the creative team to up the stakes of the story. Isolating the tight-knit community from the world beyond its borders, Morfa Halen is consistently under threat from a potentially devastating storm that could wipe out the area completely, with rising sea levels and torrential downpours putting a time crunch on the investigation and the area as a whole, which could flood at any moment.

As water fills the marshes that surround the area (Morfa Halen literally meaning “salt marsh” in Welsh), this tiny town is feeling pressure on every level.

Speaking ahead of the series, the creative team open up on how the Welsh culture and landscape became an essential part in bringing the show to life, share the efforts they made in minimizing their own environmental impact while filming, and what makes Wales so important in the story.

Under Salt Marsh creator Claire Oakley was inspired by the North Wales countryside 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.”

She later teamed up with Little Door Productions, an independent drama producer based in Cardiff, to help cement that voice. Elwen Rowlands, CEO of Little Door, is the show’s executive producer, and hired a team to find the perfect area to house Morfa Halen throughout the show’s production.

“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.

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.

But 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 £100,000 in additional sustainability funding, enabling initiatives beyond standard production practice, while production used a fully electric unit car fleet, and all departments largely using electric vehicles.

As part of the production, the team installed 13 permanent electric vehicle chargers across North Wales, which now remain in place for local communities and future productions to use, and all generators ran on 100% HVO fuel, eliminating diesel use.

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.

Once filming was completed, costumes, props and materials used were donated to Welsh charities, schools and community organisations.

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.

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.”

“Rafe and Kelly are strong actors, and I enjoyed my time with them, but working with a mostly Welsh cast and crew was a delight,” he added.

The Welsh language also becomes a key plot point 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.”

The entire production of Under Salt Marsh, under the watchful eye of Oakley and Rowlands, was rooted in Wales from beginning to end – this included the development, shooting and post-production stages.

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.”

Key locations used in Wales include:

• Mawddach Estuary

• Newborough Beach, Anglesey

• Fairbourne Beach, Gwynedd – which is surrounded by Snowdonia National Park

• Spider Island

Other elements of the show, including the wooden huts that house the community of Spider Island, were built and shot in-studio so they could film safely.

Tellingly, the areas used are experiencing similar problems like the ones that face Morfa Halen in Under Salt Marsh. Fairbourne has faced years of struggle after it was announced the area’s sea defences will be cut off by the 2050s. Gwynedd Council has since said they are planning to ‘decommission’ the area, moving everyone out by 2045 and demolishing their homes, livelihoods and roads to turn the town into a marshland.

Last year, activists in the area raised awareness after a storm damaged a concrete access point to the beach, making the point unsafe for use.

Speaking of working in the area, Stevie Herbert, production designer on Under Salt Marsh, called filming in the locations “sobering” because they were so genuinely at risk, and used these elements to create Morfa Halen.

“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.”