Is it feasible to explore Phong Nha caves sans guide? I’ve seen backpackers going in alone-did they need permits or pay local entrance fees? How clear are the cave paths, and is there any risk of getting lost without a guide? What should I know about tides, water levels, or hazardous sections? Are local villagers okay with independent explorers, or is hiring a guide mandatory? Any personal stories of self-guided trips, plus advice on gear and safety protocols, would help me decide whether to book a guided tour or go solo.