Background: I'm planning a trip into Ontario, for myself and my sister. We'll be heading up via Mackinac and Sault Ste Marie, spending a couple of days on Manitoulin Island, catching the ferry and coming down the Bruce Peninsula, and doing some things in the Owen Sound and Toronto areas. We're thinking of returning (to central Ohio) via Detroit/Toledo (since we have already seen Niagara last year). I'm thinking to cross the border at Sarnia, but I could be persuaded to cross at Windsor if there were some advantage to that.
Question: If on the way home we want to get out of the car and kill an hour or three, what are the best inexpensive things to see or do in the area south and west of Kitchiner, either in Ontario (London/Sarnia/Windsor) or on the Michigan side (Port Huron/Detroit)? Is there a particularly nice park on the shore of one of the lakes? (Huron or St. Clair would be preferred -- being from Ohio we've seen Erie scads of times -- but if the park were sufficiently nice...) What other options are available in the area?
Additional Notes: Sarah likes nature stuff (waterfalls, scenic views, etc.) but is not generally fond of a huge amount of walking -- though we're not afraid of walking a few blocks. She doesn't usually get really excited about museums, but if there's a particularly good one that doesn't take all day, that could work. Neither of us is athletic, and if we wanted to do any fishing we'll have already done it by this point in the trip.
We're relocating to Sarnia in the summer (2013) and as a keen photographer I'm interested in learning about any events that happen in Sarnia (or the surrounding region)
Thanks in advance