score:5
With a web-based Openstreetmap interface, one can use taginfo.openstreetmap.org. For example, here is the taginfo for amenity=drinking_water
. From there, one can click on Overpass turbo in the top right to be directed to https://overpass-turbo.eu/. Pan and zoom the map to the area of interest and click Run.
For example, this is the result near Barcelona Sants station:
Or in central Frankfurt, where Openstreetmap contains no results near the main train station:
Through the export-button, you can download a GPX file that you can download into a handheld GNSS-capable device.
Relevant comment by nrainer:
If you are using OsmAnd you can also show the information on the map by searching for "drinking water" and clicking on the button "show on map".