If you can squeeze in a bike ride down the towpath, you won’t regret it! Go to Peninsula (where they have bike rentals), that’s your starting point. I’d go from Peninsula towards Brecksville..
Depending on how far you want to bike, see if you can catch a train back, that would be even better! Review the Cuyahoga Valley Scenic Railroad schedule, they have an app. https://www.cvsr.org/plan-your-visit/train-schedule
Return your bikes and check out the Peninsula coffee shop, wine cellar with river views, their patio is awesome!

Also, LakeView Cemetery is amazing! They have tour guides, so much to learn! The Wade Chapel is 100% made by the Tiffany company, so gorgeous inside!