This is a huge square, or Piazza as they say, you can spend the whole day here, all the sights are within walking distance. Lots of bars, restaurants, small supermarkets, and it connects all the commercial shopping streets. All the bus terminals are not far away, so it's very convenient. It's very hot during the day, so take precautions. The tourist office is near the entrance, where you can ask for a fee for a guided tour. This is a great way to see the city.