About 100 Spanish horse riders jumped burning logs, flames leaping into the night, in a controversial, centuries-old rite celebrated every year in the village of San Bartolome de Pinares.
Crackling logs and branches lay strewn through the paved streets of the village of 600 inhabitants for the festival on January 16, the eve of Saint Anthony's Day remembering the patron saint of animals.
A parade of horses leaped over piles of branches, braving flames that danced meters (yards) high in the "purification" rite held in this town about 100 kilometres (60 miles) northwest of Madrid.
"It is really a pagan tradition. With the smoke and the fire the animals are blessed so they will be purified for the whole year and won't get hurt or ill," said Anibal Martinez, 36, who returned to his home town for the night's festivities.
No-one is certain of the origins of the tradition, which seems to have its roots in a Medieval belief that the rite protects the animals from curses and sorcery.
"According to documents in the church and town hall, we have been able to date it back up to 500 years," said Martinez, who studied the tradition when he was at school.
The town, whose population is dwindling each year, is fiercely attached to the festival despite opposition from animal rights groups concerned about the safety of the horses.
Each year, the villagers prepare the festival, gathering branches in the countryside to make bundles of sticks that will keep the logs burning through the night.
As night falls, men light the blazes and sprinkle water over the fires to create a thick, acrid smoke. The riders prepare and groom their mounts, brushing and twisting the animals' tails and manes into plaits.
When the church clock rings at nine o'clock in the evening, they gather in the village square, receive a blessing from the village priest, and join a spectacular parade through the main street, bathed in smoke and leaping over flaming obstacles.
The bravest throw their arms in the sky as their horses leap over the flames, hooves stamping on the blaze as they pass over. Others, more cautious, go around the crackling logs and just brush the fire.
"It is as much a tradition for the animals as for us," said 37-year-old Jose Maria Nunez, who came with her two children. "The animals don't suffer, they're used to it," he said.
"It is a beautiful tradition, a great feeling, you cannot describe it. You have to live it on a horse, go through the flames, feel the heat, see how the horse manages to clear it," he said.
Nunez has been coming to the festival with his horse Estrella for eight years. This year, for the first time, his son Alejandro is joining the tradition by riding the course alone.
"You have to pass the horses through the flames so nothing bad will happen to them for a year," the boy explains proudly.
Among the riders, many young people have taken up the torch from their parents and their forefathers.
At just 14, Sonsoles Hernandez Martin is one of the few girls or women to take part.
"I have been riding it alone for three years. My parents ride, too, and I have been riding with my father since I was very young, since I was two," she said.
"There is no danger. The tradition goes back to the Middle Ages and nothing has ever happened. It is a feeling you have to live through. If you don't ride, you don't live it," she said, smiling radiantly before launching on horseback into the night.