As part of the annual "Vacas das Cordas" celebrations, which stretch back 350 years, town residents chain a bull to the church, pour wine on it, and then release it into the streets.
The celebration commemorates the time when Christians turned a pagan temple dedicated to a goddess of cows into a church.
Bull running is a popular tradition in neighboring Spain, where every July thousands of people flock to Pamplona to participate in that city's famous bull-running fiesta.
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