The 100 million franc project called Heidi Alperlebnis, which was confirmed at the end of January, will be situated on the mountain resort of Flumserberg, in the canton of St Gallen.
That's just 30km away from the original Heidi tourist attraction, Heididorf in Maienfeld, over the border in Graubünden, which recreates the village where Heidi and her grandfather lived in the famous 19th century children's story.
The new theme park in Flumserberg is an attempt to harness the popularity of Heidi to boost tourism in the area.
“In the last few years the St Gallen tourism industry has suffered a significant loss in arrivals and overnight stays,” Rolf Wirth, a spokesman for St Gallen's department of economic affairs, told The Local.
The strong Swiss franc has kept German tourists away, and the region has seen fewer Swiss visitors as well, he added.
“Because tourism is of great economic value in the canton of St Gallen the government decided to take action”.
Heidi Alperlebnis was conceived as part of a cantonal plan to boost tourism in the ‘Heidiland' area, which, Wirth pointed out, includes not only Maienfeld but parts of the canton of St Gallen too.
“The new project will not represent any competition to the existing Heididorf but will complement it,” said Wirth.
Built on a mountainside overlooking the Walensee, the theme park will be accessed from the Tannenboden village, which will be redeveloped with a new cable car, underground parking and hotels.
More interactive than Heididorf, Heidi Alperlebnis will allow visitors the chance to experience what it's like to ‘be' Heidi, said Wirth. Actors will play the characters in the novel and take visitors to milk goats, craft a wooden stool and meet ‘locals' in a recreation of the 19th century Swiss alpine village.
The park will also simulate Heidi's experience of Frankfurt, where she works as a lady's maid in Spyri's novel.
The park is being developed by Swiss firm Steiner Sarnen Schweiz, which has created many tourist attractions in Switzerland including the visitor attraction at Jungfraujoch, a visitor tour at the Feldschlösschen brewery and the chocolate experience at Maison Cailler.
St Gallen authorities hope the new Heidi experience will attract some 200,000 extra tourists to the region.
The original Heidi experience in Maienfeld attracts around 150,000 each year.
Speaking to La Tribune de Genève at the end of February, the president of Heididorf, Hans-Jörg Muntener, said he didn't see the new theme park as competition, as the two Heidi experiences would be very different.
But he expressed his dismay at the “passivity” of the canton of Graubünden which, unlike St Gallen, has not done enough to capitalize on the worldwide fame of Heidi, he feels.
“Heidi is the most famous Graubünden resident in the world but our authorities do nothing to promote that and capitalize on the brand,” he said.
Published in 1881, Spyri's best-selling novel is one of the most famous Swiss works of literature.
It has been adapted numerous times for television, film and theatre all over the world, the most recent being a Swiss feature film directed by Alain Gsponer in 2015.