Back door
Entering through the back door suggests entering the house from the "shadow side," while the front of the house symbolizes its persona. The front side of the house represents who we want to be—it might be well-maintained, inviting, leading into the semi-public hall, and so forth. But the back side and back door become a more secretive, unconventional entry, one that others perhaps don’t need to know you’re using; it is the secret lover’s entrance to, say, a married woman’s house—it would be a scandal if he used the front door! (See also Backyard.)