Italy's Romanesque architecture (12th cent.) reveals the first use of the groined vault with projecting ribs. It is also typified by the development of a type of basilica having side galleries. The style was especially pronounced in Lombardy and is superbly exemplified in Sant' Ambrogio, Milan. There are two regional forms of Italian Romanesque—Tuscan (including Florentine) and southern. The cathedral of Pisa (1063–1118), with its campanile (the "leaning tower"), admirably displays the Tuscan characteristics, chief of which is the decorative use of tier upon tier of columns. Tuscan architects of the period also made a specialty of using variegated marbles and followed the antique style in this rather closely. The Romanesque of the south, as in the cathedral of Monreale, is characterized by its rich mosaics and delicate carvings, which show Byzantine, Saracenic, and Norman influences.