I have to admit I was pleasantly surprised when I stumbled onto Anderson Falls a few years ago. I didn't know there was such a large waterfall this close to Indianapolis. It's a forty-four acre park featuring a cascading waterfall (amount of water can vary significantly by local rain patterns) and two hiking paths of 1.75 and 2.25 miles.
Located just east of Columbus, Anderson Falls is easy to get to, and typically there isn't anyone else around if you go on a weekday. I've been fortunate enough to be there at times where the water was roaring over the falls, and another time in a beautiful fall setting when the entire riverbed and falls were bone dry, but covered in colorful autumn leaves.