The two church towers, reach a height of 55 metres and add to the iconic skyline of the city. In ancient times they also served a defensive and military role. One of them, the shorter of the two, is topped by a weathervane in the shape of a rooster, and because of this it is known as the «gallico». It houses the clock and bell that signal the start of the bull run every morning, called «el encierro», during the festival of Saint Fermin.