15 places within 10 km of the centre of Nam Định where you can get this for free. From the open map, updated by volunteers. Open the map to see them all and how to walk there.
Phone first if you can: hours change, and some places only open certain days.
SupportNear is a free map of free help in 1221 cities across 166 countries, in 13 languages. No account, no cookies, no cost. Places come from OpenStreetMap; if one has closed, you can mark it from its card and everyone sees it. It keeps working with no connection once you have opened it, and you can download a whole city.