Christmas present from our daughter, The Tower Bridge in London which we walk across on a Sunday morning every time we are in London. There was a problem with it and it took some time to figure it out, and no, it wasn’t a missing piece. (There are many more pieces in a tray not shown in the photo.)
The puzzling part wasn’t a missing piece, it was an extra piece. But in the end, trial and many errors resulted in all the pieces in the right place. Having enjoyed it so much we passed it on to a puzzle loving friend who has also visited London.