I always look forward to Doors Open in Toronto: there are commonly well over 100 sites open every year, many places that are completely inaccessible to the public the other 363 days of the year. A particularly good example of that is the Canadian Forces College at Armour Heights, just west of Yonge and Wilson. This is a small campus with some interesting features: they were particularly showcasing the Officer's Mess, and rightly so. I went on Sunday, and had a good time admiring the library, the lovely garden with a gun turret, a tank, and a CF-104, and also the Officer's Mess. The latter reminds me quite a bit of the University of Toronto's Hart House: it's about the same age and of a very similar stone and wood construction (although smaller than Hart House).
On Saturday I went to the Don Jail (yes, voluntarily - so many people ask). It's now the administration building(!) for Bridgepoint Health, and is a weird combination of historical preservation (several original cells, the wonderful atrium, the room where the gallows were) and bog standard office space.
photo: Don Jail - part historical preservation, part office space ...
photo: Canadian Forces College Armour Heights
More pictures can be seen here.