If you do go to Starved Rock, there are several waterfalls, actually. You can get to one or two in a short time, but most people do it as a day trip, or stay overnight. Some of the hiking is more challenging than others. I forget if that particular waterfall was accessed by one of the trails that was officially closed (due to a bridge being out) but accessible via scrambling around an alternate route, so to speak. That was also during the pouring rain, tho that part is not necessary for the experience! It gets pretty crowded on weekends, since it is convenient from Chicago, but dh and I went on a Thursday-Friday and it was a lot more manageable.