I recently was working with workflow in SharePoint Designer and I have a few Log to History actions. The workflow failed so I wanted to view the log to try and debug the problem. I went to View All Site Content and the workflow was not listed. I spent about 20 minutes trying to find the list. Finally I figured it out. The list exists but the link was just missing. So I manually navigated to the list: /Lists/Workflow%20History/AllItems.aspx.