我国最南端的城市--海南省三沙市已禁止在“三沙永乐龙洞”及其周边从事渔业生产、旅游观光活动，作为该市保护南海海洋环境的举措之一。
Sansha in Hainan , China 's southernmost city , has banned fishing and tourism in and around the Sansha Yongle Blue Hole as part of its efforts to protect the maritime environment in the South China Sea .
三沙永乐龙洞