How do I recreate the original junk folder?

All of a sudden I no longer have a junk folder. When I try to make a new one, it doesn't appear under local folders as are the drafts, sent, trash. I'm using the Eudora settings option to keep my old mailboxes (Thunderbird folders). Thunderbird list of folders is Eudora Settings: Inbox (this is active), Trash (inactive) Local Folders: Drafts, Sent, Trash (all active), Outbox (inactive), missing the Junk folder was here Eudora Import: all my old original mailboxes I would like mail labeled as junk to go to a junk folder.