The iconic musical film The Sound of Music is celebrating its 50th anniversary this year and that could mean big business for tour guides at locations where the film was shot in Salzburg, Austria.

The film, starring Julie Andrews and famous for such classic songs as Sixteen Going on Seventeen and My Favourite Things, is based on the writings of Maria von Trapp who detailed how her family escaped Austria when it was ruled by the Nazis.

Many locations in the movie are instantly recognisable for fans, including the Leopoldskron Castle, now a 67-room hotel, which was used as the Von Trapp residence in the film.

That has led to The Sound of Music fans from around the world visiting the sites and that has made money for local tours.

"After about ten years ago they found out they make money with the movie. It was already since 25 years clear that people, especially English-speaking people, are coming because of the movie, you know.

"And we had the luck that, you know, the owner was married with an American (winks) and he knows about the movie and he said we can make money with that. And so they started in 1976. Since this time we make the Sound of Music tour and it's the best tour we have," said the manager of Bob's Tours, Eviline Truhlau.

There are many sites in Salzburg that were used in the film, as Truhlau explains, "When they filmed here they really hopped around. They put things together that are not really together, by example the house.

"They used the castle, a Rococo castle, they used a Baroque castle for the front and for the back, you know. The gazebo moved in the meantime but it was built for the movie so it was used for that, it never belonged to the castle - I guess it was just the kind of thing to make something extra in this movie."

Although The Sound of Music will always be associated with the hills and mountains of Austria, the manager of the Leopoldskron Hotel claims the movie does not have quite the same level of popularity at home as it does in other parts of the world.

There are plans for more Sound of Music celebrations this year and there was even a reference to the film during Lady Gaga's Oscars performance.

Tour guides in Salzburg will certainly hope the 50th anniversary means more tourists travel to see the very hills where Julie Andrews sang her most famous line.