The Swanage Railway Line is a veritably idyllic place, and the Pier and Steam Railway it runs through were vantage points adored by perhaps its most famous literary visitor, Enid Blyton.

To mark the 70th anniversary of Blyton’s Famous Five books, a trail in their spirit is enticing everyone to take part in the sort of adventures her imagined heroes might have enjoyed, featuring six clues, a topical-sounding series of top secret stolen papers on green energy and a story based on Five on Kirrin Island Again, an instalment first produced in 1948.

“Enid Blyton loved this area and came three times a year for more than 20 years,” says Viv Endecott, the deviser of the trail who runs the Ginger Pop Shop (at Corfe Castle, where a Blyton-themed birthday party is planned in August) and Eileen Soper’s Illustrated Worlds, the Poole Quay attraction dedicated to the books.

“She knew Dorset before we gave it labels like the Jurassic Coast or Area of Outstanding Natural Beauty, and there is so much here that she would still recognise.”

Downloadable online, the trail is designed for families, with steam trains passing the route every 40 minutes.

“Famous Five adventures take place over several days and are set in big landscapes,” adds Endecott.

“I wanted the Adventure Trail to do the same so that fans get that same time and space.”

The trail runs between Poole and Purbeck and has been designed to take about two days to complete, although it could be achieved in a day “with careful planning”. Lashings of ginger beer are not included.

• Visit the trail online for all the details. Runs until November 2012.