I have created some communities in the past for testing purposes, but I am unable to delete them completely. They always appear in the side panel even though I have explicitely clicked to delete the community.
When clicking on one of these communities, the only thing I can do is to undo the deleting.
Not sure, but want to chime in because I deleted my community a long time ago and still have mod views (tabs like mod queue, unread reports, mod log) on this account.