Factual error: The mansion Allie is staying in over the summer is Boone Hall Plantation in South Carolina, near Charleston. It was built in the 1930's, so factually the house couldn't have been in the family as long as the characters make it seem. A lot of the filming was also done in Kiawah, an island near Folly Beach.
Noah: My Dearest Allie. I couldn't sleep last night because I know that it's over between us. I'm not bitter any more, because I know that what we had was real. And if in some distant place in the future we see each other in our new lives, I'll smile at you with joy and remember how we spent the summer beneath the trees, learning from each other and growing in love. The best love is the kind that awakens the soul and makes us reach for more, that plants a fire in our hearts and brings peace to our minds, and that's what you've given me. That's what I hope to give to you forever. I love you. I'll be seeing you. Noah.
Noah: Would you stay with me?
Allie: Stay with you? What for? Look at us, we're already fightin'.
Noah: Well that's what we do, we fight... You tell me when I am being an arrogant son of a bitch and I tell you when you are a pain in the ass. Which you are, 99% of the time. I'm not afraid to hurt your feelings. Because I know you'll have like a 2 second rebound rate, then you're back doing the next pain-in-the-ass thing.