Sanctum

Noun

 * 1) A place set apart, as with a sanctum sanctorum; a private retreat or workroom.
 * 2) * 1848, Charlotte Bronte, Jane Eyre, Chapter 17.
 * For myself, I had no need to make any change; I should not be called upon to quit my sanctum of the schoolroom; for a sanctum it was now become to me, -- "a very pleasant refuge in time of trouble."

Thesaurus
adytum, ashram, cabinet, cell, cloister, closet, den, hermitage, hideaway, hideout, hiding place, holy of holies, holy place, ivory tower, lair, mew, privacy, recess, retreat, sacrarium, sanctuary, sanctum sanctorum, secret place, shrine, study

Etymology
From sanctum:.