This one is a personal favourite of mine. Built in 1859-62 by Toronto architect (and later Toronto mayor) Joseph Sheard (1813-1883), this gigantic house is truly one of a kind. The owner, Nelson Gilbert Reynolds, was adamant that it be built lavishly - so much so that he paid an exorbitant sum and subsequently went bankrupt. The house had to be sold to the Methodist Church a few short years after its completion and became a school for girls, which it still is to this day.
Today, Trafalgar Castle stands out against its suburban backdrop and shows us that you can find really great architecture anywhere.
Warning: shameless self-promotion coming up...
For more information on this fantastic building, see my article titled “Storming the Castle: The Architecture of Trafalgar Castle, Whitby, Ontario” in the Journal of the Society for the Study of Architecture in Canada, Vol. 33, No. 2, 2008; pp. 43-51. Unfortunately, it’s not online, but can be found in a library near you!
For a larger image, see the "Building of the Week" section at the bottom of the page.