Around 350,000 German tourists visit Cornwall per year, but not for the reason you might expect. Rather than Poldark, German visitors are drawn to the southern-most English county because of the work of English author Rosamunde Pilcher.

In particular, Pilcher's 1987 book The Shell Seekers, set in Cornwall, sold more than ten million copies worldwide – and caught the attention of German broadcasters. Before long, German film producer Michael Smeaton commissioned the first Pilcher movie adaptation for his country's national broadcaster ZDF, based on her 1975 novel The Day Of The Storm. Then, Sturmische Begegnung, which hit German screens in 1993, was seen by nearly nine million people. Following the film's roaring success, the channel quickly commissioned ten more.

In the years that followed, a whopping 180 Pilcher adaptations – shot at various locations around Cornwall – have been made, warming the hearts of German viewers.

Riccarda and Felix Griesshammer, 32 and 33, from Nuremberg, camped in Cornwall for three weeks with their children Erich, three, and four-month-old Hedwig this summer.

They visited Pencarrow House, a classical stately home with gardens near Wadebridge – and used in several Pilcher films, most notably as a winery in 2011's English Wine. Mrs Griesshammer told the Daily Mail: "We know about Cornwall because of Rosamunde Pilcher.

"Germans, when they hear about Cornwall, they know it. There's nothing you have to look up on the map, 'Where is it?' You somehow know what to expect."

Her husband added: "In Germany, when people think about Cornwall, they associate it with Rosamunde Pilcher."

Visitors Yvonne Fritz and Elizabeth Angliker said Pilcher's influence spread across the German-speaking world.

The friends, from the German-speaking part of Switzerland, near Zurich, said Pilcher is also popular in their country, as well as in with Austria.

"If you say, 'Rosamunde Pilcher', people say, 'Cornwall', and the opposite, if you say you travel to Cornwall, 'Ah, Rosamunde Pilcher'. Everybody knows. It's very famous," Ms Fritz revealed.

She went on: "All the movies are running in the afternoon at 4pm. People can watch them again and again. It's always on TV."

In fact, such is the popularity of Cornwall with German speakers, two-thirds of all foreign visitors to the county are Germany, Austria or Switzerland, the tourist board in harbour town Padstow said.