📜 Concrete bombproof cave, built 1963-65. 🔍 Served as hospital and safe house during Vietnam War. Invisible from road and air, it was strategically important. # Why Go ✨ Explore a three-story bombproof cave 🏥 See an operating theatre, recovery rooms, and a cinema room 🗣️ English-speaking guides available 🏝️ Popular attraction on Cat Ba Island 💰 Very cheap entrance fee # Why Avoid ⚠️ Steep, uneven stone steps at entrance/exit 🚗 Difficult to access without private transport # Tips 🛵 Rent a scooter in Cat Ba town (100,000 – 150,000 Vietnamese Dong) for easy access 🚕 A taxi from town is another option # Cost 💰 15,000 Vietnamese Dong entrance fee.