Noun

1. The innermost, secret or hidden parts.
2. The innermost parts of a building, such as a shrine, recess or a sanctuary within a temple.
   • 1748, Tobias George Smollett, The Adventures of Roderick Random

     I believe, had I been in the inmost recesses of my habitation--the very penetralia--your eagerness would have surmounted bolts, bars, decency, and everything.