What an interesting question! Of course, Rebecca in this excellent novel is a rather fascinating character, because she never once appears in the flesh, rather living on in the imagination of the unreliable narrator that tells us this story and also in the memories of other characters, such as Mrs. Danvers. When I first saw this question, my immediate response was to link the house of Manderley with Rebecca, and having thought about it, I want to stick to this initial response. The house of Manderley is somewhere where the narrator never feels comfortable. It is marked by Rebecca's indelible presence and routines, and she is always made to feel lacking or wanting when she compares herself to the way Rebecca was and how she managed Manderley. In addition, if we look at the way Manderley is introducted when the narrator first arrives there, there is a distinct sense of fear and doom in the way it is described. Note how even the drive, as described in Chapter Seven, gives this sense:
The drive twisted and turned as a serpent, scarce wider in places than a path, and above our heads was a great collonade of trees, whose branches nodded and intermingled with one another, making an archway for us, like the roof of a church. Even the midday sun would not penetrate the interlacing of those green leaves, they were too thickly entwined, one with another, and only little flickering patches of warm light would come in intermittent waves to dapple the drive with gold. It was very silent, very still.
The drive is compared to being a serpent with its obvious allusion to evil, temptation and deceit. The trees keep the drive from light and warmth, plunging it into a kind of darkness, which could be metaphorical of the darkness that the narrator endures for most of the novel. The character of Rebecca seems so bound up in the character of Manderley itself, that it is only natural to think of Manderley as being a kind of motif for Rebecca herself. I always think of "The Fall of the House of Usher" and the way that the deaths of Roderick and Madeline result in the "death" of the house itself, and the same could be said with Manderley's end. When the phantom of Rebecca is finally killled off, Manderley dies with her.