At that time, Zhang Baozai, the great pirate, commanded 40,000 troops and four big ships of the Wuse Gang, and took the lead in the South China Sea under the banner of "opposing the Qing Dynasty and destroying the foreign countries" and "robbing the rich to help the poor". In the first year of Jiaqing, they took Lantau Island as their nest, went in and out of the Pearl River Estuary, and carved the words "Wan Hai Ping Bo" and "Shengong" on Dong 'ao Island. Twenty years later, Jiaqing was suppressed by the Qing army and evacuated from Dong 'ao Island. It is said that when they left, they buried 18 boxes of treasures near the stone carving, which were divided into "eighteen lines of hidden treasures and eighteen lines of travel" for future return. Where the treasure is has always been a mystery. So, the island left such a ballad: "There are eighteen boxes of jewels and eighteen rows of boxes. Who can get it? Drink porridge early and slaughter sheep late. "