I Capture The Castle was shot at Manorbier
Tenby doubles for aristocratic, 1930s Suffolk in a new movie penned by the author of 101 Dalmations.
I Capture The Castle is a pre-war English love story, following the fortunes of an eccentric, hard-up family struggling to survive in their dilapidated castle home.
But it is 12th Century Manobier Castle, near the Welsh seaside resort, which doubles as the historic abode in the big screen conversion of Dodie Smith's classic novel.
And film chiefs say it is just one of a new wave of new Brit flicks keen to use Wales' heritage attractions as shooting locations.
Cassandra, 17, narrates the movie through the writings in her journal, detailing her family's huge back-rents and her father's struggle to repeat the success of his best-selling novel, written some 12 years earlier.
It had to be slightly run down, it had to have a moat and it had to be in a rural setting
When two American brothers inherit their home, they are thrown into financial disarray, but Cassandra and her adolescent sisters fall in love.
"We looked at five or six castles and chose Manorbier for a number of reasons," said Oscar-winning producer David Parfitt (Shakespeare In Love).
"It had to be slightly run down, it had to have a moat and it had to be in a rural setting."
Nestled in a narrow valley, coastal Manorbier was the perfect choice, a lavish Norman residence which remained unscathed through an uneventful battle history.
But that ideal isolation also offered up its problems.
"One of the first problems we encountered was how to line and fill the moat with water," adds Parfitt.
"The only water supply at the castle was a tap, and it would have taken years to fill this moat with buckets.
"So we ended up hiring a water tanker in London (there weren't any available locally) and bringing our own water from London!"
Once the moat was full, film newcomer Romola Garai had to swim in it.
"I have to say that swimming in the moat was purely a test of physical endurance," she said.
"And sunbathing on the roof of the castle when the wind was whipping across was quite similar."
Playing Cassandra, Garai shares the screen with Rose Byrne (Star Wars: Episode II), Henry Thomas (Gangs Of New York) and Marc Blucas (Sunshine State).
Developed by BBC Films and Trademark Films, the flick was also shot on the Isle of Man and London.
With hundreds more castles, Wales is well-placed to lure similar future productions.
The movie is told through Cassandra's journal
Out of the tourist season, many heritage sites double as movie locations for directors lured by the Wales Screen Commission, monuments agency Cadw and the National Trust.
"Manorbier Castle looks very romantic and alluring," said the commission's Carys Hedd.
"We also tend to have lots of enquiries about beaches.
"The closing scene of the latest Bond movie was shot on Penbryn Beach near Cardigan.
"They built a grass hut on a cliff overlooking the sea - a stand-in for North Korea."
I Capture The Castle opens around the UK on 9 May.