Cát Bà Island

The largest island in Hạ Long Bay, Cát Bà spans about 285 square kilometres and contains a national park protecting a rare mix of coastal karst, tropical forest, mangroves, and coral reef. The island's freshwater lakes and cave systems are remnants of its geological complexity, and it shelters the critically endangered Cat Ba langur, one of the rarest primates on Earth. Kayaking from Cát Bà town into the surrounding bay provides access to fishing villages and secluded beaches unreachable by larger tour boats.