A door in a dream usually represents a choice standing in front of you -- an opportunity you can step through, or a transition you're still deciding whether to make. A locked or unreachable door can reflect an option that feels closed off, while an open one often signals readiness.
We shall not ignore the 120 conjunctions that occur between the planets, because in them its almost the whole knowledge of what happens in the world of being and corruption. - Ptolomeus