In 1924, after an inspiring trip to Italy, prominent tuberculosis physician Dr. Jarvis Barlow commissioned Wallace Neff to design a two-thirds replica of Villa i Collazzi, southwest of Florence, for himself and his wife. The original is sometimes attributed to none other than Michelangelo. (Unfortunately, Diane Kanner's otherwise excellent book on Neff mistakenly pictures a very different-looking villa on Lake Como as the model.)
Villa i Collazzi outside Florence [via Flickr user aldoaldoz]
Neff evidently felt comfortable editing the supposed Michelangelo masterwork, scaling down the overall size while emphasizing the windows, doors, loggias and courtyard. The mottled color was achieved by mixing pigment into the wet stucco.
The Barlow house is now part of the campus of Alverno High School, a private Catholic girls school. (Thanks to Alverno for the links to the photos.)
The school grounds are open on weekends and the building's exterior can be studied at length in situ—just watch out for frequent wedding parties. It's cheaper than a flight to Italy and as close as you're likely to get to a Wallace Neff without being nabbed by security guards.