For starters, and obvious reasons, it’s where the book started so this location brought it full circle. But also, it resembles the change in Victor. At the end of the book Victor is so obsessed with finding the monster he becomes as cold and ruthless as the frozen environment that the monster has lead him to. This obsession is instilled in Victor because he has no social life or social connection to friends. The monster does this to victor by killing William, Justine, Henry and, finally, Elizabeth. It almost seemed like the monster wanted to make Victor feel as lonely as he was. He wanted Victor to know how he felt.