The weed sways as the wind blows over the dry landscape of Aragón, in north-eastern Spain. Thousands of sheep bells disrupt the peacefulness of the scene as the herd relentlessly cruises over the ridge. Dark clouds pour rain over Ramón Costa's faithful umbrella and the dusty track turns into an arduous path of ankle-deep muddy puddles.

Shepherd tracks like this one are now almost forgotten, but used to be the main routes for livestock transport until the end of the 19th century, when the advent of modern transportation brought herding into the industrial era. Ramón uses them every year, when he walks his herd the 100 km from the winter pastures of his farm in Monzón to the summer pastures in the Pyrenees.

In the same way as it has been done for thousands of years.