A turret is a lookout above the rest of the house, read as a wish for perspective, solitude or a romantic escape. Being shut in one stands for isolation, as in old tales.
When this appeared in your dream, what were you feeling?
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.