Things I learned on a Sound of Music tour around Salzburg, Austria: Christopher Plummer didn't actually sing Edelweiss for the film; he refused to carry young Gretel (actress Kym Karath) up the mountains in the final scene because she was "too fat"; and all of the film's interior scenes were shot in Hollywood.
This last fact is important when you're on the Sound of Music bus tour, with dirndl-wearing guide and singalongs, as it means the tour includes quite a few blink-and-you'll-miss-it drive-bys of iconic sites. That's because in most cases there's little point in SoM fans going inside, as the interiors don't appear on film.
But for any Sound of Music geek, the tour is still a must-do, filled with great tidbits of filming trivia, plus it's simply a great way to see the sights of Salzburg.
I thought I knew all there was to know about the Sound of Music. I've seen the show in London's West End and even spent a summer playing a nun in a professional production of the musical. I watched the film so many times as a child that the videotape wore out, and I've read books about the real von Trapp family.
But even with that background knowledge, a Sound of Music tour through the Salzburg is packed with a wealth of information.
For those who don't know, the movie - shot in Salzburg in 1965 - is based on the true story of Maria von Kutschera, a nun, who was sent to the house of Captain Georg von Trapp to tutor one of his children or, as portrayed in the film, to be a governess to his seven children. The pair fell in love and, with the children, formed the Trapp Family Singers who later fled Austria when the Captain received a summons from the Nazis to join the German Navy.
First stop is the Nonnberg Abbey - where, in the film, Maria lived as a nun, and where the real-life Maria and Captain married. We squint to see a red roof several hundred metres up the hill and fail. Disappointing. The next sight isn't much better - Frohnberg Palace (the facade of which was filmed for Maria's arrival at the von Trapp house) is viewed from across a field as the bus whizzes past, but by the time we reach Leopoldskron Castle (used for the lake and gazebo scenes at the von Trapp house), things improve.
We are off the bus, although we're still across the lake, and the building looks amazing. By now the guide is regaling us with tales of filming - including one involving actress Julie Andrews and the children doing take after take falling into the freezing cold lake.
The next stop is Hellbrunn, now home to the gazebo, which used to sit at Leopoldskron. It was moved when the castle's owners became tired of fans sneaking in for a bit of a sing in the middle of the night.
After a quick photo session outside the gazebo and a compulsory impromptu solo of the song Sixteen Going On Seventeen, we wander the tree-lined path where Maria danced her way through I Have Confidence.
This is more like it. And if we're reliving musical moments from the movie, the ultimate has to be having Climb Ev'ry Mountain blasting out of the speakers as the bus climbs into the mountains that overlook the glassy lakes below.
We soon arrive in Mondsee to the church used for the film version of Maria's wedding. It is also the place where the von Trapp children are seen hanging out of trees dressed in their home-made clothes. At this point the men on the trip, who until now have pretended to be unimpressed, liven up, as this is also the stop for some of the finest apple strudel you'll ever taste.
From there it's back to Salzburg and the famous Mirabell Gardens, which fans will recognise from several of the movie's scenes, Do-Re-Mi included. The gardens are a beautiful spot to spend time in the city, whether you're an Sound of Music fan or not. I wander around singing "The Hills Are Alive", wondering if learning all this about the film has dimmed my love of it.
It hasn't, although I will never quite look at Christopher Plummer the same.