This area of the South China Sea is filled with towering limestone krasts and caves. It is the Ministry of Tourism’s top promotional item, but it looks much better in photos than in real life. Being so close to China and so much industry, the sea here is hopelessly polluted. And the town that tourists launch from is about as tacky as Niagara Falls. It is a UNESCO World Heritage site, but the UN is considering revoking this designation because of the pollution and overdevelopment. Vietnam is trying to figure out how best to cash in on this attraction without destroying it in the process.