The top is Lake Erie, and the bottom is the
Ohio River. The upper left corner is where
Toledo sits, right against Michigan, south of Detroit. The upper right corner is (roughly) where you'll find Cleveland. Go a little further and you'll hit Erie, PA, and beyond that, Buffalo, NY.
The lower left corner is Cincinnati, across the river from the most northern part of Kentucky. Smack dab in the middle of Ohio is Columbus.