Both the mosaics and the villa’s ambitious plan make it a sight worth seeing. There are forty-two polychrome pavements, involving the setting by the ancient workmen of 30,000,000 individual mosaic rectangles, or _tesserae_, over an area of more than 3500 square yards, a complex unique in extent in the Roman world. The plan, too, is one of the most ambitious known to archaeology, rivalling that of Nero’s Golden House, Hadrian’s villa, or Diocletian’s palace at Spalato on the Dalmatian cost. The villa lies three-and-a-half miles southwest of Piazza Armerina, nearly 2,000 feet above sea level, on the west slope of Monte Mangone, in the midst of green orchards and pleasant groves of nut trees. Its altitude assured its being cool in summer; its setting under the lee of the hill protected it from winter winds. But the slope required terracing, and so the villa was laid out on four levels centering on three peristyles and a portico (plan 2,15,41,26). The parts are connected by irregular rooms (13,14,40). The technique of the masonry shows that the whole complex is of one build, characterized by asymmetrical symmetry, strange, twisted ground-plans, a fondness for curves, and off-center axes, all of which shows a definite break with conventional classicism. The structure is light and elastic: the dome over the three-lobed state dining room (46), nowadays replaced by an unnecessarily ugly modern roof to protect the mosaics, was built of pumice concrete, lightened still further by setting in it lengths of clay pipe and amphorae, to reduce the weight of the superstructure on the bearing walls. [Illustration: FIG. 13.2 Piazza Armerina, Imperial Villa, Gismondi’s reconstruction. (Pace, _Mosaici_, p. 33)]