A friend sent me a link to some info about the house that’s almost as much fun as the house itself. The page on the DuPont Castle website (which has lots of info on other American castles, it seems) has a picture of the house along with tons of emails with various wildly differing stories about the house and its history.
There are some bits of information that sound more accurate than others.
It’s located on the corner of Cagle Rd and Hwy 140 in Roswell, GA.
I looked it up in Google Earth, and lo and behold, found it. Here’s a snapshot from Google Earth (links to the bigger version in my flickr stream).
From the overhead picture, it’s now clear that yes, indeed, there is a real swimming-pool moat around the whole structure.