To see a door in a dream is an expression of security and the level of protection in general. If a closed door is seen in the dream, the dreamer feels safe or wants to protect her/his beloved ones. If the door is seen open in a dream, it means just the opposite.
Seeing a Iron door in a Dream
If the iron door seen in the dream is locked by the dreamer her/himself, it means that the person has something very valuable to hide behind locked doors. Although the dreamer is very worried about its safety, she/he does not give up on his precautions.