This is the Mercer House, the one that appears in the movie Midnight in the Garden of Good and Evil.
It is an amazing typical house from Savannah, with beautiful ceilings and big rooms, ball rooms, living rooms, and it has a pipe organ inside, within a wall.
Not only it is the house that appears on the movie, but it is the original house where the story actually took place (the movie tells the story of Jim Williams, a very wealthy man that lives in this sumptuous house and where... well, I can't tell the movie story here, just watch the movie!).
A place that everyone must stop by in Savannah.