The Palio di Siena is a historic bareback horse race held twice each summer in the central square of Siena, Italy. It features ten horses and riders representing the city’s neighborhoods, competing in a frantic 90-second sprint.

First, on July 2: Known as the Palio di Provenzano, honoring the Madonna of Provenzano.

Second on August 16: Known as the Palio dell’Assunta, honoring the Assumption of Mary.

Siena is split into 17 historic neighborhoods or contrade, but only 10 compete in each race (7 automatically and 3 chosen by lot) and the race goes through the city’s main sloping medieval square.   It is transformed with a heavy layer of packed dirt and clay over the cobblestones.

Jockeys ride bareback for three intense laps around the square, covering a total distance that takes roughly 90 seconds.  Virtually anything goes during the scramble once the starting rope drops; jockeys can use their whips and hinder competitors.

For a quick look at the incredible pageantry, crowds, and fast-paced chaos of the event in the main square, try this video from Rick Steves.