In Grimsby you can relax. Play golf, go hiking on the "Bruce Trail" - please stop in time - otherwise you end in Tobermory which is approximately 640 km away. Try to purchase the great photographic book from Peter Fowler which guides you along the "Bruce Trail". Certainly there are also other good books available.
If you are not a hiker just stroll around in one of the beautiful parks or along the gorgeous waterfront.
Buy fresh local fruits of the season. This area is famous for it.
Unfortunately more and more houses had been built and less and less land is available for agriculture.
Fortunately, Ontario has now started to protect the so called "Green Belt" in the Niagara Region.
There is so much to discover. Just go to a tourist office and collect actual information.

Visit also the "Beamer Memorial Conservation Area" and enjoy a beautiful natural scenery. Unfortunately I do not have any pictures because I did not have my camera with me when we stopped there.
When you are in downtown Grimsby use Regional Road 12 which guides you to the escarpment and do a right turn when you see on your left the "St. Mary's Ukrainian Church". Follow after that the posted signs.
Especially the area around Grimsby is known for growing fruits and when you buy them ripe they taste really good. But you have to go to a fruit stand and try it before you purchase if that is allowed. Take some with you on this tour. You cannot buy any food or drinks in the conservation area.
Be prepared to walk a lot.
Enjoy fauna and flora. You will also find two water falls. Do not forget your camera as I did!