Cuyahoga Valley National Park
The park is a nice spot for some mellow day hikes. Mostly the trails are through an established hardwood forest that was carved up in interesting ways by the glaciers that used to frequent the area.
Think of it as a shady woods, with mossy sandstone cliffs and rocks, with some streams and waterfalls.
If you were just walking the trails leisurely, most trail heads can be explored in under 3 hours, giving you the chance to then drive to another part of the park and explore some more. It has some fantastic hikes, wonderful waterfalls, and contains part of one heck of a bike trail.
Just keep in mind that the park is designed around visitors taking a quick day trip from one of the surrounding cities.
Most everything is a short walk from a parking area, with a heavy focus on picnic spots for families. The bike trails are flat. Road biking between trail heads/destinations is possible, but keep in mind the roads are two lane with a minimal shoulder and folks tend to drive a bit fast.
There is a great farmers market there and some of the most dedicated volunteers. The area around Cuyahoga Valley National Park offers additional opportunities that those other areas do not offer. It is also bordered by several Cuyahoga and Summit county metroparks that are also great.
It’s a great place to visit, but I’d definitely rank it in the bottom third of U.S. national parks, though that’s not necessarily an insult. It’d be like ranking in the bottom third of your class in Harvard.
You still graduated Harvard.