Duomo di Milano By Paolo da Reggio at it.wikipedia . - Own work , CC BY-SA 3.0 , Link Lombardia, Italy. The naturalistic, artistic and architectural panorama of Lombardy offers tourists numerous visits. There are five UNESCO sites on the regional territory: Mantova , the city of the Gonzaga and Sabbioneta, the "ideal city" of the Italian Renaissance; the Sacri Monti, devotional route in the Varese and Ossuccio areas; the prehistoric cave paintings of Valcamonica; the Rhaetian railway that crosses the mountain landscapes of Albula and Bernina ; the nineteenth-century industrial settlement of Crespi d'Adda and, finally, Milan , where, in the beautiful church of Santa Maria delle Grazie you can admire the fresco of the Last Supper painted by Leonardo da Vinci . Also in Milan, the regional capital, important architectural works are the Teatro alla Scala, the famous stage of world opera, the Castello Sforzesco, and the monumental Duomo, the white marble church