I was on a holiday in Prague, Czech Republic. I was walking on the Charles bridge and taking random photos of the city.I didn't notice anything at the time. Only when I looked back at the photos, I've noticed something strange.I knew it couldn't be a bird or a plane because it was pretty big and very flat. I was amazed when I had discovered it. Quite shocked as well. Since I haven't noticed anything in the sky at the time, I just walked away. What I know for sure is this. This is not a bird or a plane but a real UFO.