overall it looks decent, tho I do have a few minor issues with it
first, I would follow the [unknown] guidelines and put the caves’ name in [brackets], i.e. [mountain cave in Switzerland] or so
on that note, I probably would have created a place for that specific cave, not for all the caves in Switzerland. might make it a bit tricky since we don’t know the name (as mentioned above), but that’s preferable to what’s currently entered, in my mind. I wouldn’t create a worldwide place for all the caves of the world for similar reasons
I would use the [unknown] location, credited as mountain cave in Switzerland.
Because, as nobody know what cave it is, we will never be able to add a second relationship to this place.
So it’s better to not have a place for only one relationship.
I guess potentially someone could ask the choir what cave this was - to be honest, I suspect many people from Switzerland with an interest in caves could tell from the video alone.