To see an unknown person in your dream signifies a part of yourself that is repressed and hidden. Alternatively, it symbolises the archetypal dream helper who is trying to offer some insight and advice. 

To dream that you are in a strange, unknown or foreign place represents change in your life. Consider how you feel about the surrounding. If you are afraid or lost, then it indicates that you are not ready for the change. You are not ready to leave the past behind. If you are excited or happy in this unknown place, then it suggests that you are ready for change.