When Inigo and Wesley are doing the sword fight on the Cliffs of Insanity, at one point, Wesley swings on a bar. First of all, why would there be this random bar on a cliff? And second, the bar is flexible, like they use in gymnastics.
Okay, it amazes me that you actually thought that was supposed to be a metal bar. It was obviously a vine of some sort between the trees. And this movie is a fairytale, if you're going to be picky about stuff like that, you shouldn't be watching the movie in the first place.