The walkway is above the main hall, along the walls and over the door, and can be used as a viewing area for the altar. What is the architectural term for that?
I'm not sure if I'm allowed to post a picture, but it's the best way to describe what I mean. I'm lj-cutting it.
EDIT: I think either "mezzanine" or "gallery" will work. Thanks! I'm kicking myself for not being able to find that out myself.
EDIT AGAIN: "Clerestory" is exactly what I was looking for. The character would know the term, so he'd use that over the other options. Thanks!