Excellent hiking and interpretive trails.
From Columbus take I-71 north to the Polaris Exit. Exit to the right on Polaris Parkway, heading east. Turn left on Worthington Road. Then turn left on Africa Road. You will be able to see the dam at Lewis Center and Africa Roads. Turn left onto Lewis Center Road to get to the Below Dam Recreation Area or the U.S. Army Corps of Engineers Visitor Center.
http://www.tripleblaze.com/trail.php?c=3&i=6088