Hang Tien cave in the UNESCO World Heritage Site of Phong Nha-Ke Bang National Park. After a trek through the jungle and traversing the pitch black of Hang Tien cave we emerged the other side to be greeted by this scene. As part of my first time travelling, after dreaming of this kind of adventure for years, reaching the other side of the cave and being met with this sight was a hugely special moment. The most memorable part of a truly transformative experience.