The Towpath area of the Cuyahoga Valley National Park has long been a favorite for my family.... my mom grew up on a farm just across the street, where the giant movie theatre is now! My old dog, Ollie is buried somewhere near Hoggys....
Bring your bike down to the towpath and check out the remains of the locks on the Erie Canal. You can find all kinds of interesting wildlife living between the canal and the river. There's even a small museum with a restored section of the lock near the trailhead in Valley View. If the museum is open, I recommend checking out the miniature working display of the canal in the basement.... I remember checking this out with my grandma in the old museum 25 years ago!