The web team for the Lord of the Rings Online has published another of their Exploring Middle-earth articles. The focus of this installment is an Edain mount in the Great Barrow, "Othrongroth":

In the southern reaches of the Barrow-downs lies the Great Barrow, Othrongroth, one of the oldest and largest of the Edain mounds. For many years the Dúnedain of Cardolan protected it, until a great sickness arose from the south. This plague devastated Cardolan, leaving the ancient burial-mounds vulnerable to the horrors of the Enemy.

You can read the article here, or here from the European site.