Dating from the Middle Ages, this spectacular annual event includes a series of colourful pageants and a wild horse race in Piazza del Campo. Ten of Siena's 17 contrade (town districts) compete for the coveted palio (silk banner). Each contrada has its own traditions, symbol and colours, plus its own church and palio museum.
From about 5pm on race days, representatives from each contrada parade in historical costume, all bearing their individual banners. For scarcely one exhilarating minute, the 10 horses and their bareback riders tear three times around a temporarily constructed dirt racetrack with a speed and violence that makes spectators' hair stand on end.
The race is held at 7.45pm in July and 7pm in August. Join the crowds in the centre of the Campo at least four hours before the start if you want a place on the rails, but be aware that once there you won't be able to leave for toilet or drink breaks until the race has finished. Alternatively, the cafes in the Campo sell places on their terraces; these cost between €350 and €400 per ticket, and can be booked through the tourist office up to one year in advance.
Note that during the Palio, hotels raise their rates between 10% and 50% and enforce a minimum-stay requirement. To join a Palio-focused guided tour and learn all about the event from a local, contact the Centro Guide Turistiche Siena e Provincia.