Ettenmoors
From Tolkien Gateway
The wild, untamed lands that lay north of Rivendell. It was here that the Witch-king of Angmar fled after his defeat in the Battle of Fornost. It is said to be the home of Trolls.
It is speculated that Mount Gram, which is where a host of Goblins attacked the Shire from, was located in the Ettenmoors.