The tour itself was great, the only reason I gave 4 instead of 5 is that the Emerald Cave is just a small, 10-15ft nook in the wall of the cave. It only glistens emerald when the weather, sun, time of day, etc. all lines up correctly. So when we were there, it was basically just a regular part of the wall. That being said, the day was wonderful and I'd definitely do it again with my updated expectations! So if you want to spend a morning kayaking down a beautiful river, and seeing Emerald Cave at it's peak would just be the cherry on top, then definitely book this. If the only reason you are going is to see Emerald Cave at it's peak, then there is a good chance you'll be disappointed.