Il Palio di Siena In the 14th century, a big horse race was organized that crosses the entire city. Around 1500, all 42 “contrade” of the time were called upon to take part in the Palio. In the 17th century, the event was transformed, from a horse race across the city to a race around Piazza del Campo. The Palio is still an event that involves all the Siena inhabitants, who get busy with the preparation many months before the race, which attracts thousands of tourists from all over the world each year.