Middlesex Court House
Erected in 1830, this building was modelled after Malahide Castle, near Dublin, Ireland, the ancestral home of Colonel Thomas Talbot, founder of the Talbot Settlement. The site was a part of the town plot set aside by Lieutenant-Governor John Graves Simcoe after his visit to The Forks in February, 1793. Here he proposed to locate the provincial capital.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.