A film-maker has revealed how a crumbling set of Second World War structures off the Kent coast provided the inspiration for his new dystopian blockbuster.

Producer Ben Pullen started to develop an idea for an initial script based on the Maunsell Forts, off Herne Bay, after driving along Thanet Way when he moved to the area.

The forts are a series of armed towers in the Thames Estuary that operated as Army and Navy bases from 1942 to protect London from sea and air strikes.

He told KentOnline: "The first time you see them, it is like what on earth is that.

"I started looking at pictures of them and discovered everything about the forts."

From there he came up with an idea for a horror film which followed a group of teenagers who decide to climb up the structures after a party and then started to get picked off one by one.

He pitched it to writer-director Malachi Smyth who "hated it" and instead told the film-maker to leave it with him. Eight weeks later a script for what was originally called Gateway Six was sent back to Ben.

"It was completely inspired by the Maunsell Forts," Ben said. "To develop it from that, I accessed funding from Screen South, in Folkestone, and the Kent Film Office, in Maidstone.

"Screen South is an amazing place. It it the first place people should go to if they are based in the South East and are interested in film-making to see what help they can get.

"And The Kent Film Office is the go to place for people thinking to film in the county.

"It was thanks to them both I had enough money to develop it into a script and then it took many many years."

Gateway Six was eventually developed into sci-fi, dystopian thriller Last Sentinel and was filmed two years ago in Estonia.

Set in 2063, where climate change has had a catastrophic impact on the world, a group of soliders are defending their home from an invasion by an enemy they have never seen.

Alone on the forts, the tensions between them start to rise when a mysterious boat comes into range.

Directed by Tanel Toom, it features actress Kate Bosworth, Blue Lights actor Martin McCann, German actor Thomas Kretschmann and Netflix's Emily in Paris star Lucien Laviscount.

But the film's early development also coincided with personal tragedy for its producer.

Ben explained: "It coincided with my third son Silas getting ill with cancer and then two years later passing away. That took many many years out of my life.

"When I was eventually ready to get back into the saddle I picked up Last Sentinel again and off we went."

His son Silas died in 2013 from a malignant and aggressive brain tumour when he was 11-years-old and mum Sarah went on to write a book about her son and the pain of losing a child.

The family, including brothers Oscar, Inigo and Rufus, went on to raise more than £400,000 for the Brain Tumour Charity in his memory.

Ben, who lives in Faverhsam, added: "At the end of the film, at the end of the credits, there is a big dedication to Silas.

"It is such a challenge getting any film made right now but to be an indie film producer is a real challenge so it took a lot of perseverance, dedication and a crazy amount of time to get this going.

"In a way, it was Silas that kept me motivated and indeed kept those around me motivated.

"Sometimes my producing partners, especially Pippa Cross, would flag every now and then and she would say 'no you have got to do this for Silas'.

"It became a rallying call for us and we wanted to do it for Silas. He really helped us get it over the line."

Ben started producing films a few years ago but before that was a budding actor.

He decided to change careers to spend more time with his family and have more control over his diary.

"It brings fresh challenges and has been very fulfilling. I am still glad I did it all these years later," he added.

Last Sentinel will be released for purchase online in the UK on Monday April 24 following its international release earlier this year.