Morningstar Mill gives St. Catharines a heritage stop with a proper landscape around it. The restored mill stands above DeCew Falls on the Niagara Escarpment, where machinery, stonework, and rushing water explain why this was a useful place long before it became a scenic outing.
It works especially well if you are already exploring Short Hills or the escarpment edge. The site is small, but it has texture: an old industrial building, a waterfall, and the sort of local volunteer care that makes a historic place feel lived-in rather than sealed off.