I like the story how you didn't actually noticed that and then it caught your attention on the photo and it made you go back and learn more about it :) This is the beauty of little things that make our life richer.

I've been to Kalemegdan a few years ago and I loved it. We booked a tour with a very funny guy. The tour ended in a bar nearby as he was very curious about people from different countries :)

It looks like you had a great time in Belgrade too :)