Board Thread:Suggestions forum/@comment-26149161-20170221225823/@comment-25841881-20170224040408

Gandalf, logic and sense dictates that they'd have foreign smithies and mines, not just in the Barad-Dur area. Melkor would not need those, as his raw materials all came from inside his great fortresses. Sauron, however, had materials coming from all over the place, and so it would be more practical for him to have refineries closer to the sources..