Gabriele, It's a very good try. Keep this kind of thing up and you'll do very well. You obviously have a good eye for it. You've composed the picture very well, except for the missing top of the arch. To me, the downsides are: (1) Pushing the color saturation usually is a bad idea. In this case the walls worked out okay, but you ended up with a wildly over-saturated sky. The greenery in the background is unrealistically green also. (2) The birds were a good idea, but they're awfully small. The situation is helped by the roof-line on the right that points downward toward the birds, but it's not quite enough. The bird thing is a minor point. With the rest of the arch and the saturation toned down it would be a very compelling picture.