Gryffindor

While venturing along the seventh floor, one might wander upon a portrait of a rather heavy set woman, if she's not asleep or away in staff antechamber chatting with her friend Violet ... say the right words and she shall open and reveal a place that Gryffindors have learned to call home. Just beware, the Fat Lady does remember faces, and while that is a saving grace to a Gryffindor who forgets the password, it is an assured answer that this is not a place a member of another house will be able to sneak into.