The Vesuvian towns are the greatest source for our knowledge of how people lived in the ancient world. With its hundreds of houses, re­sidential villas and small, scattered farms reaching up to the slopes of the mountain, Pompeii has always been at the centre of studies on Roman dwellings and of every attempt to bring their inhabitants back to life through the imagination in novels, plays and films. The Roman house was, however, much more than an architec­tural module or a source of finds for archaeologists and antiquarians. It was the fundamental unit of a complex social system, the heart of widespread religious beliefs, the custodian of an aesthetic vision of the world. What the eruption of 79 AD halted forever is a fragment of that world, knowledge of which has never ceased to astonish later generations.