Once a year, deep in the rural countryside of the French department of Cantal, some 40,000 people amass in the small village of Allanche.
Normally, the town is home to just 800 people, but every May, the streets swell with crowds, and the air fills with the sound of cowbells, as a centuries-old tradition gets underway: the transhumance of Salers cattle to the high mountain pastures.
