sanctums
n. (寺庙或教堂的)圣所( sanctum的名词复数 ); <口>私室
If you refer to someone's inner sanctum, you mean a room which is private and sometimes secret, where they can be quiet and alone.
His bedroom's his inner sanctum.
卧室是他的一方净土。
A sanctum is the holiest place inside a holy building such as a temple or mosque.