I'm guessing that this is the same problem that we had on other wikis, namely that the information is stored in a place where it is not accessible over the API. Perhaps @MaxSem, our maps and geo expert, can shed some light on this.

First results of the source code analysis. The code uses a special query to the Wiki API to determine the nearby articles, such as the following (based on the coordinates of the capital Yerevan):

https://en.wikipedia.org/w/api.php?action=query&prop=coordinates&format=xml&colimit=10&generator=geosearch&ggscoord=40.1533904|44.4885671&ggsradius=10000&ggslimit=10

This call returns a list of article while it does not work for the Armenian Wikipedia:

https://hy.wikipedia.org/w/api.php?action=query&prop=coordinates&format=xml&colimit=10&generator=geosearch&ggscoord=40.1533904|44.4885671&ggsradius=10000&ggslimit=10

It seems that there is a problem of the Mediawikis of some languages which does not provide the coordinates of the articles. Does anyone know how the coordinates go from the article to the API?

Further analysis: Even the retrieval of the coordinates of a single article is not possible on Armenian Wikipedia: https://hy.wikipedia.org/w/api.php?action=query&prop=coordinates&format=xml&colimit=10&titles=%D4%B5%D6%80%D6%87%D5%A1%D5%B6

I generated a ~200 items list of Wikipedias that do not return coordinates via its APIs. It is based on a geosearch around New York City.

The list contains beside many very special languages also many commons languages of the Caucasus, Balkan, Eastern Europe and Asia that are not supporting coordinates. I am wondering if there is another way to solve this issue than to contact each admin of the different Wikipedias separately.

With the great help of hywiki user ԱշոտՏՆՂ the problem has been solved for Armenian Wikipedia. This required the adaption of several templates. The question is how this can be done for all the other Wikipedias? I see three possibilities with different pros and cons:

1. Someone with more power than me pushes/motivates/supports local admins of the related Wikis to do the required changes in there templates
2. Coordinates template is somehow standardized so that it must be used on every Wiki
3. Wiki-Api returns available coordinates of the related Wikidata item if no coordinates on Wikipedia is available
4. Wikipedia App uses Wikidata coordinates if no coordinates on Wikipedia is available

In T89703#1732782, @Aschroet wrote:

With the great help of hywiki user ԱշոտՏՆՂ the problem has been solved for Armenian Wikipedia. This required the adaption of several templates. The question is how this can be done for all the other Wikipedias? I see three possibilities with different pros and cons:

1. Someone with more power than me pushes/motivates/supports local admins of the related Wikis to do the required changes in there templates
2. Coordinates template is somehow standardized so that it must be used on every Wiki
3. Wiki-Api returns available coordinates of the related Wikidata item if no coordinates on Wikipedia is available
4. Wikipedia App uses Wikidata coordinates if no coordinates on Wikipedia is available

I think #1 would be the best. Could you compile a new list? Hopefully it would be shorter. (Removing Android app tags as this is not an app bug but a site issue.)

Nearby was removed almost two years ago (T228661). It’s probably time to decline this task, unless Nearby is likely to come back (which I would very much appreciate!).