4th year overnighter Adventure

Our Ward/Stake has never done a 4th year overnighter or other activity, and doesn’t plan to. So as camp leaders we want to start doing something for them, and decided the sky’s the limit. We want to make it an experience to remember so they feel they have gotten to do something really special to commemorate the end of their certification before becoming a youth leader. I want the girls coming up next year to also be excited for when they get their opportunity. We have a camp site reserved close by, but I want to do more, or something different then camping. Any ideas?