St. Thomas' Church 1838
This church is one of the few surviving structures in Ontario built of "rammed earth". This method of construction utilized wet clay mixed with chopped straw, compacted into forms and covered, when dry, with plaster or siding for protection against weather. Built in a plain, somewhat Romanesque style, the church was begun in 1838 and largely completed by 1841, although not officially opened until February 27, 1842. Lieutenant-Colonel Edward O'Brien, leading member of the Shanty Bay settlement, donated the church site and clergyman's residence, and directed the construction of the church. He and his wife, Mary Sophia, are buried in the adjacent cemetery. The Reverend S. B. Ardagh served as rector from 1842 to 1867.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.