The most striking feature of the city is the Duomo, the large, white-marble cathedral (1386–1813), which shows traces of many styles (especially Gothic). It is elaborately ornamented, with 135 pinnacles and more than 200 marble statues. A statue of the Madonna is on the highest pinnacle (354 ft/108 m). Other points of interest in Milan include Brera Palace and Picture Gallery (17th cent.), which includes major works by Mantegna, Bellini, Piero della Francesca, and Raphael; the Castello Sforzesco (15th cent., with 19th-century additions), which houses a museum of art; the Church of Santa Maria delle Grazie (1465–90), containing the famous fresco, the Last Supper, by Leonardo da Vinci; the Basilica of Sant' Ambrogio (founded in the 4th cent., rebuilt in the 11th–12th cent.); the Ambrosian Library, which houses a rich collection of paintings; the Church of Sant' Eustorgio (9th cent.); the Leonardo da Vinci Museum of Science and Technology; the gallery of modern art; and the Poldi Pezzoli Museum, with paintings by Boticelli, Pollaiuolo, Mantegna, and Piero della Francesca. Long a center of music, Milan has a conservatory and a famous opera house, Teatro alla Scala (opened in 1778). Between the Duomo and La Scala is the 130-year-old Galleria, an enclosed four-story glass-roofed arcade that contains shops and eateries and is a popular gathering place. The city also has three universities and a polytechnic institute.