Ha Long bay - Cat Ba island located in the Northeast of Vietnam, in the area of Ha Long city (Quang Ninh province) and Cat Hai island district (Hai Phong city) is the largest limestone island in Vietnam. Features of biodiversity include the seven typical ecosystems of tropical limestone islands, namely tropical rainforest ecosystem, cave ecosystem, mangrove ecosystem, tidal ecosystem, coral reef ecosystem, soft-bottom ecosystem. Ha Long - Cat Ba also represents a high level of species diversity with 4,622 species of plants and animals on land and in the sea.
