alt Hacker NewsDisclaimer: I work for the Wikimedia Foundation, albeit in the infrastructure rather than in development / product.
I like this feature a lot, but I do not know how it is implemented and whether it would be possible to have users change the range. Maybe it is hardcoded for some performance reason, I have honestly no clue. But I am giving below a few paths that could help one eventually improve the system.
The page https://en.wikipedia.org/wiki/Special:Nearby is powered by the MediaWiki extension https://www.mediawiki.org/wiki/Extension:NearbyPages .
The source code is https://gerrit.wikimedia.org/g/mediawiki/extensions/NearbyPa... (GitHub mirror https://github.com/wikimedia/mediawiki-extensions-NearbyPage... ).
Issues/bugs are tracked at https://phabricator.wikimedia.org/tag/nearbypages/ , it is possible a similar request already exists there.
Do note I am not in the development / product side and I have no view about their backlog or whether they have the bandwidth to review such an incoming review request or a patch.
Replies
The Special:Nearby feature seems to support changing the language. nearbywiki.org is just English while the OP has a language switch but it's limited.
Now I'm not sure if switching the language pulls in more results or just changes the article language...
For what it's worth, the actual search backend seems to be implemented in the separate "GeoData" extension: https://www.mediawiki.org/wiki/Extension:GeoData
That extension exposes a public API that allows setting any search radius up to 10 km ( https://en.wikipedia.org/w/api.php?action=help&modules=query... ), so presumably there's no barrier to making the search radius smaller, but maybe there'd be performance issues if you allowed making it larger.
(NearbyPages just embeds a Vue app into the page that makes a client-side fetch() call to invoke that API with a hard-coded radius.)