Welcome to Canada! Specifically, Rondeau Provincial Park.
Located directly above Ohio, on a sand spit jutting out from Ontario and into Lake Erie, Rondeau is less than a six-hour drive from Cincy. And it's absolutely beautiful. There are tons of cabins to rent and the hiking, swimming, and beautifully clean beaches are definitely worth the drive. (Just don't forget your passport!)
If you want to find out more, visit www.ontarioparks.com/park/rondeau.