I'm doubting this is the arsenale of Venezia, and looking in a desultory way for other possiblities, including maybe somewhere in the Lido area.. or, indeed, in some other cities.
.. not sure how I came across this, but suddenly I have a website that is marking the disturbing changes wrought by sulfur over not much recent time - http://www.ourvenice.org/?hlangs=en
(The town harbour in fact as opposed to Gruz where most cruise ships dock. The largest boat you can see in my picture with the red top is the tender to a Silver Seas deluxe cruise ship which takes its passengers right into town)