Ironmane's Lock (WAR History and Lore)  

This is a Destruction only unlock which requires you to use one of the Rock Lobbers on Lobber Hill. When you land, head down the first ramp, take a right and run down the second ramp. Another right at the bottom of the second ramp and you should see a Memorial Plaque mounted on the wall. Interact with this plaque to trigger the unlock.

History & Lore in Mount Bloodhorn