is surrounded by a number of buildings utilizing this stone, now often hosting open-air markets. Depending on the position of the Sun and the Moon, its color is constantly changing. A few blocks away, the Piazza Arringo, or piazza dell'Arengo, was the administrative and religious center of the town, surrounded by the Cathedral, the baptistery, the Bishop's residence, and the Palace of the Commune. According to traditional accounts, Ascoli Piceno once housed some two hundred towers in the Middle Ages: today some fifty can still be more evidently seen. Main sights include: Churches and convents Cathedral of Sant'Emidio, dedicated to Saint Emygdius, houses an altarpiece by Carlo Crivelli. Tempietto di Sant'Emidio alle Grotte Tempietto di Sant'Emidio Rosso San Francesco: gothic style church begun in 1258. The dome was completed in 1549. A monument to Pope Julius II is in the side portal, while the central portal is one of the finest examples of local travertine decoration. Adjacent to the church is the 16th-century Loggia dei Mercanti, in Bramantesque style of the Roman High Renaissance. Convent of San Francesco: adjacent to the above-named church, of which two noteworthy cloisters remain today. It was once a prestigious center of culture, whose students included Pope Sixtus V. Sant'Agostino: 14th century church built originally with a single nave, was enlarged with two aisles in the late 15th century. The rectangular façade has a 1547 portal similar to that of Sant'Emidio. The convent houses the town library, the Contemporary Art Gallery and an auditorium. San Cristoforo is a Catholic baroque church located in the historic center of the city. San Domenico: former convent, now school, has a Renaissance cloister with 17th-century frescoes. Santa Maria Inter Vineas: 13th century church San Pietro Martire: 13th century church with a 1523 side portal by Nicola Filotesio, known locally as Cola d'Amatrice. The interior contains the precious reliquary of the Holy Thorn, a gift of Philip IV of France. San Tommaso: 1069 Romanesque-style church built with spolia from the neighboring Roman amphitheater. San Vittore: Romanesque church documented from 996 with a low bell tower. Edicola di Morelli: Monumental baroque niche attached to the exterior of the church of San Francesco at the Piazza del Popolo. The niche housed a venerated Madonna image, putatively designed by Lazzaro Morelli, a disciple of Gianlorenzo Bernini. Secular buildings The Palazzo dei Capitani del Popolo ("Palace of the People's Captains"). Built in the 13th