We will be travelling with a very large group to Kauai. We will be staying at the Grand Hyatt in Koloa. Most of our days will be pre-arranged but we do have one day to ourselves and have rented a car. Where should we go and what should we do/see? We're in our early 50's. We're not the zip-line type, but love anything outdoors. We are on Kauai for such a short period of time, we just want to be sure we don't miss a "must do"....Thanks!!!!