A sanatorium is a quiet place for long rest and recovery. Tradition reads it as the wish to withdraw and recover your strength, away from the demands of everyday life.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.