Ninh Bình Province
Hainanpotamon vietnamicum is a species of crab. Originally described as a species of "Geothelphusa", it is now treated as part of the genus "Hainanpotamon", although it has also been suggested as a member of "Tiwaripotamon". It is only known from a single locality in Cúc Phương National Park, Ninh Bình Province, Vietnam.