I took these photos two weeks back while on holiday in St. John's, Newfoundland. While going for an early morning jog up Signal Hill, I detoured off the road and passed Queen's Battery, an 18th century fortification guarding the harbour.
Maker's stamp on one of the cannons. Sure looks to me like this was made in 1708, unless I am misreading it. If so, that's about as old a piece of wesern military history as one is likely to come across in Canada.
Both photos taken with my iphone 4.