After this jury I definitely know what I do not want the project to be (an archive)!
I work on the plan now, so it starts to suggest some kind of alternative usage/program. Some of the vaults should contain buildings, some program, some are empty. I found these amazing plans of transilvanian castles & sketches by Kahn, that work with mass/solid relationships. problem is light: maybe some vaults have a oculus like the one in the mexican cave we saw… any thoughts??