The Italianate/Italian Villa style of architecture here is really interesting and definitely unique to still be standing in this era, in this region. The multiple stairwells, combine with the shape of the house and its service entrances make for an interesting wandering experience.
The house used to be home to Canada's first Prime Minister, John A. MacDonald. However, in general, it provides an interesting look into Ontario life in the 1840s (pre-confederation).
The property itself is beautiful as well. Be sure to check out the gardens where gardeners work in period costumes.