Domus Aurea, the Golden House. The name conjures up a vision of splendour, which even a visit to the gloomy vaults beneath the southern slopes of the EsquiIine cannot altogether dispel. All too little has survived ; and unless there are surprises in store for us still below ground, it seems unlikely that we shall ever know very much more about it from the actual remains than we do at present. But with each year that passes fresh knowledge accumulates in other, related fields. Vision shifts and perspectives change, and every now and then it becomes worth while once again to take stock, to ask which of the old problems still matter, and to see what are the new ones that have now to be considered. The present article, which lays no claim to originality, is an attempt to present and assess the present state of scholarly opinion about what must, by any computation, be held to be one of the most important buildings in the whole long history of classical architecture.