Bronze cannon for possible ID

[fernando]

I wonder if the guys within this area are around ...
This cannon was found some thirty years ago at 3 Kilometers from my hometown (Portugal Northern coast), a couple hundred meters from the shore.
A couple young divers, maybe for reasons due to its large dimensions (some 3 meters) decided to give it to the local Naval club; not without resistance from the next city and even Lisbon Museums.
It has been placed at the inland historical club entrance for some thirty years and later moved to the club's marina restaurant entrance, a much more recent construction.
For reasons connected with lack of investigation interest, neither the divers nor the club management (a rather small institution) ever cared to identify this cannon which, in my humble opinion, belonged in a foreigner ship. All i managed to know so far is that there are more where this one came from, although of cast iron, reason why the young divers had no interest in bringing them up, aware that special equipment and immediate treatment were required.
I have taken a couple poor pictures with the intention to post them here in the forum, with the remote hope that its details would sufficient to identify its possible age and provenance.


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