Finding gap in "unclosed multipolygon"

Could anyone help check where this multipolygon is unclosed? Zoomed all around it but couldn’t find the gap

many thanks

1 Like

I think one segment was in there twice.
Can you please check it?


Even if you don’t use it for editing, JOSM’s relation validation is really useful. Just download the object and click the “validate” button (and maybe a bit of adjacent data for context), and it’ll tell you what’s wrong.

It validates OK after @Kogacarlo’s edit.


I wanted to chime in with Andy (@SomeoneElse) about JOSM and how it is the best relation editor out there, hands down. (Well, this is one person’s opinion, mine). Even without the “Validate” button, JOSM’s relation editor will display a “red-shaded” double-occurrence of a member, which should be deleted (as it appears it was in this case). However, if you use this “sub-editor” to display the relation, click the “Sort” button, and for all of the “outer” role-tagged elements, these should cause a “loop” in the right-most connectivity display (an excellent feature). If it doesn’t, you can “scroll to the end” of where these elements are, finding the “end of the linestring” and that will be one of the elements that makes the polygon “unclosed.” (The other end of the linestring is the other member that makes it unclosed).

A bit hard to describe in words, but you’ll see it. When you get the hang of it you won’t have any more unclosed multipolygons: it’s that effective a feature in this sub-editor. Use JOSM for editing relations!


thanks everyone, and Kogacarlo for fixing it:)

just tried the relation editor and i see the loop after sorting. I should probably familiarise myself with JOSM in general

Personally, I use the Potlatch 3 relation editor, but it doesn’t have JOSM’s validator…