The façades, on the other hand, were treated as independent decorative compositions, and were in many cases remarkably beautiful works, though having little or no organic relation to the main structure. The most celebrated are those of +Sienna+ (cathedral begun 1243; façade 1284 by _Giovanni Pisano_; Fig. 151) and +Orvieto+ (begun 1290 by _Lorenzo Maitani_; façade 1310). Both of these are sumptuous polychromatic compositions in marble, designed on somewhat similar lines, with three high gables fronting the three aisles, with deeply recessed portals, pinnacled turrets flanking nave and aisles, and a central circular window. That of Orvieto is furthermore embellished with mosaic pictures, and is the more brilliant in color of the two. The mediæval façades of the Florentine Gothic churches were never completed; but the elegance of the panelling and of the tracery with twisted shafts in the flanks of the cathedral, and the florid beauty of its side doorways (late 14th century) would doubtless if realized with equal success on the façades, have produced strikingly beautiful results. The modern façade of the Duomo, by the late _De Fabris_ (1887) is a correct if not highly imaginative version of the style so applied. The front of Milan cathedral (soon to be replaced by a new façade), shows a mixture of Gothic and Renaissance forms. +Ferrara Cathedral+, although internally transformed in the last century, retains its fine 13th-century three-gabled and arcaded screen front; one of the most Gothic in spirit of all Italian façades. The +Cathedral+ of +Genoa+ presents Gothic windows and deeply recessed portals in a façade built in black and white bands, like Sienna cathedral and many churches in Pistoia and Pisa. [Illustration: FIG. 151.--FAÇADE OF SIENNA CATHEDRAL.] Externally the most important feature was frequently a cupola or dome over the crossing. That of Sienna has already been mentioned; that of Milan is a sumptuous many-pinnacled structure terminating in a spire 300 feet high. The +Certosa+ at Pavia (Fig. 152) and the earlier Carthusian church of Chiaravalle have internal cupolas or domes covered externally by many-storied structures ending in a tower dominating the whole edifice. These two churches, like many others in Lombardy, the Æmilia and Venetia, are built of brick, moulded terra-cotta being effectively used for the cornices, string-courses, jambs and ornaments of the exterior. The Certosa at Pavia is contemporary with the cathedral of Milan, to which it offers a surprising contrast, both in style and material. It is wholly built of brick and terra-cotta, and, save for its ribbed vaulting, possesses hardly a single Gothic feature or detail. Its arches, mouldings, and cloisters suggest both the Romanesque and the Renaissance styles by their semi-classic character. [Illustration: FIG. 152.--EXTERIOR OF THE CERTOSA, PAVIA.]