A blog by a couple travelling around Europe. They describe a Roman villa in southern Spain, with similar ones in Portugal. Dated to the 1st century AD, these villa appear to be partly rammed earth on a masonry base.
Rammed earth is apparently mentioned in the Roman dictionary of architecture (Vitruvius – de Architectura), but I could not find it when I looked. It is described by Pliny, who discusses the watchtowers in Spain constructed by Hannibal. In ‘Earth Construction: A Comprehensive Guide’, Roman rammed earth remains are discussed at a number of French archaeological sites.
I’ve written a brief history of rammed earth around the world, to be included in my thesis. If you know of any more historic rammed earth, please let me know.