Though this trip was focused on social elements (visiting with friends), as soon as I saw a sign for "Fort No. 1", I had to go. It turned out to be right up my alley - an 18th & 19th century fortification with full visitor access, and even permission to use tripods.
A few of the original guns were still emplaced - all aimed towards the US border, as the assumed assault would come from across that line.
By far my favourite setting in Fort No. 1 was the gun emplacements that looked into the moat - the light in the space was wonderful (though I still wish there had been a way to turn off the modern lighting).