Thousands of sheep and goats fill the streets of Madrid during an annual festival celebrating the ancient practice of moving livestock to new grazing grounds.

MADRID — Thousands of sheep and goats thronged the streets of the Spanish capital on Sunday, drawing large crowds of tourists and locals alike to watch an annual festival recreating the pastoral practice of moving livestock to new grazing grounds.

Madrid sits on an ancient migration route that has always been part of a vast grid of farming paths covering the Iberian Peninsula. Open fields and woodland crisscrossed by droving routes once covered the area where the city now stands.

This year, the Transhumance Festival took a detour from its traditional historical route to avoid the city’s central square, the Puerta del Sol, where housing activists have set up a protest camp.

The housing protests gathered pace last month, fueled by outrage over the eviction of an 87-year-old woman from her home of seven decades in downtown Madrid. The woman, María del Carmen Abascal, widely known as Maricarmen, died in hospital shortly after her eviction.

Avoiding the protest camp, the livestock were driven through the streets of central Madrid to the sound of bells and bleats. The festival also spotlights the environmental benefits of traditional grazing, in which livestock are used to clear brush and other flammable undergrowth, reducing the spread of wildfires. The movement between seasonal pastures is called transhumance.

However, it is in decline as Spain’s interior experiences a population exodus which started around 1950, as generations of young people left the countryside in search of work and opportunity in cities.

Madrid has held the festival since 1994. Towns and smaller cities in Italy, France and California hold similar events. In Spain, modern farming methods have reduced the practice of transhumance to a small group of farmers that keep the tradition alive not just for its environmental benefits but also for its cultural value.