There's only one spot where the speaker can bring himself to say straight out that Annabel is dead (that's in line 26: "killing my Annabel Lee"). For the rest of the poem, this "sepulchre" is his way of talking about death. It stands in for all of the horror of death, and gives the speaker a way to talk about losing her without explicitly saying it. (It's also an extra cool-sounding word as far as we're concerned. It has a great spooky, Halloween feel to it, doesn't it? It would also be a great name for a metal band.)
- Line 19: If the kinsman represents the society that tries to keep these lovers apart, the sepulchre is a symbol for the cold reality of death. Notice how Annabel gets "shut up" in this tomb. It's a harsh phrase that makes it sound more like a prison than a final resting place.
- Line 40: At the end we are left with only the sea and the sepulchre. With their similar sounds, the words seem almost married to each other, a pair like Annabel and the speaker. Notice that the kingdom and the sea are a pair at the beginning but now the sepulchre has taken over, and death has replaced life.