Two 60-year olds (me and my partner) went on the zipline adventure and we enjoyed ourselves. It is not at all strenuous, the zip lines are pretty close together and the zip line is not very fast. There is a thrill to experience when you soar above the treetops, but not recommended for those who have a fear of heights, especially during the walk across the rope bridge. I'm not sure we'll zipline around the world, but it was a worthwhile experience - once.