Siena - a Little Town in the Heart of Tuscany
The Piazza del Campo is one of the most beautiful main squares in Europe, and composes the heart of the town. Shaped like a sea-shell or a princess' veil (depending on your imagination) The Piazza is the chosen location for the famous horse race, the Palio (which is such an event I have a separate description). Il Campo will invite you to linger and imagine all the stories that have taken place here (My wife and I had our first date there). There will be many others sunbathing or enjoying an ice-cream (the best ice cream in Siena is at a little home-made ice cream place called Il Gelato just below vicolo San Paolo). In the evening, the square becomes an open-air bacchanalia. You can buy a bottle of wine at Vini+Dolce where they will open it for you and supply you with cups if you are so inclined.
The Duomo is another important landmark, not far from Piazza del Campo. In addition to the remarkable facade, the marble inlaid floors are a chef d'oeuvre, but they are only fully uncovered for a month every year.
The best way to see Siena is by wandering through the streets, and looking carefully at details not just landmarks. You will always find something new (well, it's been there for ages) be it a fresco or a shrine.
If you wander long enough you will get into the spirit of the city and begin to be entranced by its medieval mystery.