You can easily (for some value of 'easy') add a link from a page on Wikipedia to a page on LocalWiki.
When adding a link on a Wikipedia page to a LocalWiki page, you should format it as follows:
[[localwiki:<region_short_name>/<page_url>|link text]]
For example, to link to the LocalWiki page for Golden Gate Park ("Golden_Gate_Park") in San Francisco ("sf"), you would write:
[[localwiki:sf/Golden_Gate_Park|Golden Gate Park]]
Basically, just copy & pate everything after the "localwiki.org/" part of the URL, e.g.:
https://localwiki.org/sf/The_Wiggle
becomes:
[[localwiki:sf/The_Wiggle|The Wiggle]]
on Wikipedia. Horray!