One of the highlights of our Vietnam visit was a couple of hours underground in Paradise Cave. I was spellbound by the sheer size of the place and the incredible shapes that formed naturally over millions of years. The cave is 31km long, we only walked through the first kilometre. It was nicee and peaceful for the majority of the time, as we left, thousands of tourists descended into the cave, ruining the peaceful enjoyment we were lucky to experience. One of the most incredible places I have ever been.