I noticed earlier today that most of the museums in Birmingham were
not showing on this query (they are now!):
https://query.wikidata.org/#%23defaultView%3AMap%0ASELECT%20DISTINCT%20%3Fi…
This was because they were not shown in Wikidata as a museum (or
subclass thereof); some were simply marked as "manor house",
"factory", "water mill", etc. Or it was because they had no
"located
in the administrative territorial entity"(P131) property.
You might like to check your local museums, or those you've worked with.
--
Andy Mabbett
@pigsonthewing
http://pigsonthewing.org.uk