Thanks for all your comments. The bridge is not in Cambridge but about 12 miles to the West at St.Ives. (This is the St. Ives that the old riddle was based upon, "As I was going to St. Ives, I met a man with seven wives .......)
The building with the blue light was in fact a Chapel which did, actually, have another bit on top but caused it to sink further into the river (R. Great Ouse), so was removed. I think the powers to be thought it would be good to have a blue light inside, the era when blue light was new and cool!
The whole reason for not cropping was to create a "puzzle" feeling. So I guess that bit works
That bridge has been a cause for a number headaches over the years. Even Cromwell had a part of it demoished during the Civil War.... !