Double Haven or Yan Chau Tong (Chinese: 印洲塘) is a harbour hugged by Double Island, Crescent Island and Crooked Island with north-eastern New Territories, Hong Kong, China. Major parts of the haven falls within Yan Chau Tong Marine Park to protect the wildlife of the marine creatures. It is renowned for its scenery and unspoilt natural beauty. It is also renowned for its calm seas even during stormy weather, thus the English name. Double Haven contains many deep red coloured rocks. This is because of iron oxide.