On a chilly January night, hundreds of people gathered on the steep and narrow cobblestoned streets of San Bartolome de Pinares — population 500 — to watch a dramatic sight: horses galloping through towering flames.

It's a centuries-old tradition in the Spanish village about 100 kilometers (60 miles) northwest of Madrid that takes place every year to honor St. Anthony the Abbott, the patron saint of animals. Riders guide horses through bonfires lit in the middle of the street in an act believed to purify the animals in the coming year.