Lansdowne Iron Works
While the existence of local ore was well known and various petitions had been made for the right to erect a foundry, it was not until 1801 that Wallis Sunderlin, a Vermont founderer, established the first iron works in Upper Canada at Furnace Falls. The works, which included both a furnace for the production of cast iron and a forge for the manufacture of wrought iron, were operated with limited success by Sunderlin and his associates until destroyed by fire in 1811. Attempts in 1815-16 to re-establish the works to supply the Kingston dockyard were ended with the agreement to limit armaments on the Great Lakes.
Plaque via Alan L. Brown's site Ontario Plaques. Full page here.