I can give you some ideas for KY and TN. The Smokies aren't within the circle you drew, but if you love scenic natural settings, I'd highly recommend a visit (and recommend avoiding Pigeon Forge unless you're into outlet shopping and mini golf). Red River Gorge & Natural Bridge state parks in Eastern Kentucky are gorgeous & great for hiking, camping, and climbing. Mammoth Cave is a lot of fun and incredible to see (I'd recommend the spelunking tour if you're physically able). The drive through central Kentucky on I-64, especially between Frankfort and Lexington, is full of rolling green hills & horse farms. It's even prettier off the interstate on the back roads in the Versailles, Midway, & Nicholasville area. The Cumberland Gap area on the KY-TN-VA border is supposed to be beautiful, but I've not been there (yet). I think that's east of the circle you drew, though.