This was filmed in Ireland, for whatever reason. But anyone who lives in the Southeastern United States, or Georgia specifically, the way you can tell this is not Georgia, and not the Chattahoochee National Park, is that through the whole movie there's not one single pine tree. It's all hardwoods. When the lumber barons (the Vanderbilts specifically) ravaged the Appalachian mountain range of many old growth trees, pine trees were planted to prevent erosion.

With the exception of extras, very few Irish actors were cast in the movie. The entire film was made in Ireland

src: IMDb Trivia

I wonder why they choose to film in Ireland instead of just Chattahoochee National Park, USA. Maybe some "programs" by the Ireland government that will help with production costs?