Are they collected from different forts ?
Cheers nessy.
Not really. Fort Anne itself dates back to when the French built it in the 1700s, and it swapped hands several times (the area has more history than most of Canada could wish for, from Port Royal [where Samuel Champlain and Sieur De Monts set up in 1605, to Fort Anne, Bloody Creek etc]. In all Fort Anne has about 20 cannons, from 18 pounders, to a host of cannonades, the nice Strassbourg cannon shown above (chained in place), and the mortar, as well as a pair of field guns down near the town hall.
A good number of the guns had been collected together and held in the area until the War of 1812, when the government set up two batteries on either side of the Digby Gut, to prevent Americans from getting into Annapolis Royal and Digby. At the time the bulk of these cannons were pretty much obsolete, and were hauled down to the batteries, and after the war just left there. When Fort Anne was established they decided to haul the guns on the Annapolis side back to Fort Anne (1930s IIRC). The guns on the Digby side were left laying in the woods where the battery had been until the 1980s, when they were finally hauled down and put on display in Digby (two by the cenotaph, and IIRC 8 by the water front). They are all 18 pounders (again IIRC). [I had pics of all of them but lost them in a crash of my PC]. I think Fort Anne got one or two early on from Halifax, but can't say for certain.
In general the Maritimes is still pretty well stocked in old smoothbores, from Citadel Hill, to Fort Beausejour, and a large number of other sites. PEI in particular is swamped in cannons when you think of them at cenotaphs, town halls, legions etc, from WW1 field guns, to 1700s smoothbores. On top of that, there are even a number of 18 pounders in private hands in the Maritimes.
Fort Anne:
http://www.pc.gc.ca/lhn-nhs/ns/fortanne/natcul/histor_e.asp