In the world of dreams the rules of reality do not necessarily apply. Each dream is unique and it's a direct link to the soul and spirit. Psychology provides its own theories on what dreams mean, but so did tradition and the study of dreams for thousands of years before any relevant science had developed.
Dream Meanings - Watchtower
To dream you are in a watchtower means you will make great and tiring efforts to achieve something that preoccupies you. If you see soldiers in a watchtower then be careful as some in your circle are trying to create obstacles for you at work.