So I've stumbled across a secret room. After jumping around in the antheon throne room I found it actually hidden in a wall on the left hand side. This could quite possibly be a room that could store another chest. By the look of the room it looks like it was made for a purpose. It's not easy to get to but it's easy enough that you could get there for a chest. Will keep updated. Update. I've made a 30s clip on my xbone. If you would like to see then go to my profile and watch. Gt - sgt chubb brown.