Is there a widest thing on Earth? I find that we don't account for width - there is the tallest, longest, deepest and largest things around the world and in the universe. There is a biggest thing in the universe.
The biggest thing in the universe is the Hercules-Corona Borealis great Wall, first reported in 2013. It is so big that light takes about 10 billion years to move across the structure. In comparison the universe is 13.8 billion years old. That is big and wide.
On the simple scale of us humans, there are lots of big things to visit nearby. I found a website that lists all those 'big thing' statues in Canada - there are lots of them. Nearby is the Niagara Falls Flower Clock - it made the list. There are Snowmen, Apples, Moose, Cows, Muskie, Muskoka Chairs, Saws, etc. all over the province.
The big item really is the changing colours of the leaves across the landscape. The escarpment shows off the colours beautifully.
The colours are moving past their peak in Algonquin Provincial Park with 100% change and leaf fall of 60%. The Ontario parks.com site doesn't include any provincial parks in Niagara - perhaps our colours are not as dramatic as others in Ontario. That certainly would be the case with northern forests. Here's their pretty chart on peak viewing.
I took a picture of the floral clock - so here it is today - with the large hydro-electric grid in its background. And then we have two examples of our pretty colour display in Niagara - the informal and extensive pumpkin and chrysanthemum festival.