 The population remained nearly stable until the mid-20th century, when a huge immigration flow from southern Italy had it increase from the c. 15,000 of 1961 to the some 45,000 of 1971.The "frazione" of Stupinigi houses the famous Palazzina di Stupinigi, part of the UNESCO list of World Heritage Sites.The castle, also known as "Palazzo Occelli" (1565), is also notable.