Hi Helena, thanks for your comment on my shot!
I'm no expert, but a couple of things to maybe think about... rotate it so that the verticals of the buildings are in line with the verticals in the reflection.
I've just done an adjustment but can't upload it - if you click on modification then people can do varaitions for you - I've found it really helpful for some of my shots!
Next, maybe try curves to give the image more depth and contrast. also a bit of dodging/burning to pull out selective areas like the foreground cobbles and wall. There is an add on for photoshop called silver efex pro - which can really bring the best out in mono.
The shot has a great lead in and nice reflections and is a good subject matter for mono!
Anyhow, just a few ideas - don't know if they are helpful or not...
all the best