Tags in Mail Sidebar?

A Tags element has/seems to have suddenly shown in in my Mail sidebar. (inboxes, favorites, tags, etc.).

The sidebar is already about a meter long and I want to remove the Tags element. I’ve looked where I think a setting should be, but now wonder whether removal possible.

Thanks for clues!


Snappy response, Gary! Many thanks!

I foolishly thought that, since the Mail sidebar is unique to that activity, a control like this would be in the Mail settings area.