Founded in the Middle Ages, when the population of the ancient Turris Libisonis gradually took refuge in the hinterland, Sassari emerged on a limestone plateau marked by valleys and gorges and surrounded by cultivated hills. Olive groves and woods complete the setting of the fifth largest territory in Italy. It is the city with the second biggest population in Sardinia (128 thousand inhabitants), the heart of an area that contains double this number. It became a Municipality in 1294, with the promulgation of the Statutes of Sassari, which represent a fundamental body of laws in the history of the Island. In the 19th century, it expanded beyond the fourteenth-century walls that surrounded it, linked by 36 towers. Six of them still remain. The La Marmora barracks were built in place of the castle, now the museum of the Sassari Brigade, protagonist of military events in the 20th century.