Its proximity to New Orleans (about 30 min. away), in-character docents, and appearance in Interview with the Vampire have made Destrehan Manor a popular plantation jaunt. It's the oldest intact plantation home in the lower Mississippi Valley open to the public. It was built in 1787 by a free person of color for a wealthy Frenchman and was modified between 1830 and 1840 from its already dated French colonial style to Greek Revival. Its warmly colored, graceful lines are aesthetically pleasing.
The tour, led by costumed guides (it's better than it sounds) is worth taking. The house stayed in the original family's possession until 1910 (some female descendants are still on the board that oversees the place), so a fair amount is documented, and some of the furnishings (including a table used by Lafayette) are original. One of the rooms has been left deliberately unrenovated, and its messy deconstructed state shows you the humble rawness under the usual public grandeur. Important note: This is perhaps the only plantation that is truly accessible for those with disabilities; there are entrance ramps and an elevator to the second floor.