A remarkable example is the =Palace of Diocletian at Spalato, Dalmatia=, built <small>A.D.</small> 300. The plan, rectangular in shape and covering an area of 4½ acres, about the same, in fact, as that of the Escoriál in Spain, seems to have been laid out on the lines of a Roman camp. A square tower occupies each of the corners, while three of the sides were pierced with entrances, flanked by octagonal towers, which were distinguished as the “golden,” the “iron,” and the “bronze” gateways. From these extended colonnaded roads which met in the centre, thus dividing the area into two northern sections, probably used by the principal officers of the household and the guests, and a large southern portion reserved for the imperial palace, and two temples. One of these was dedicated to =Æsculapius=; the other, circular in plan, to =Jupiter=. The architecture was of a somewhat debased character, but offers certain interesting features of transition to the later style of the Romanesque. Thus, in the northern gateway an entablature is not employed, and the arches rest directly on the capitals of the columns. =Domestic Buildings.=--The domestic architecture comprised three forms: the _domus_, or city residence of the well-to-do; the _insula_, or city tenement house, and the rich man’s country house or _villa_. The last term comprises the house and its accompaniments of beautifully laid-out grounds and gardens. On a colossal scale of magnificence was the =Villa of Hadrian= erected at =Tivoli=, where the whole area amounted to seven square miles. It included, besides the usual palace apartments, a gymnasium, thermæ and theatre, disposed amid terraced gardens, peristyles, ornamental water-basins, and fountains.