The United Nations Educational, Scientific, and Cultural Organization (UNESCO) added Vietnam’s Ha Long Bay - Cat Ba Archipelago to the World Heritage List on Saturday night (Vietnam time). Ha Long Bay - Cat Ba Archipelago is Vietnam’s first inter-provincial UNESCO-listed world heritage site. Cat Ba Archipelago in Hai Phong, a major port city in northern Vietnam, is the largest limestone archipelago of the country. It includes over 360 islands, including Cat Ba Island to the south of Ha Long Bay. Ha Long Bay - Cat Ba Archipelago is Vietnam’s first inter-provincial UNESCO-listed world heritage site.