The Clérigos Tower rises 75 meters high, it was the tallest building in the city. It has a carillon of 49 bells acquired in 1995. In addition to serving as a bell tower, this building had other uses over the years: it served to mark the time (through a daily shot of dry powder that marked noon); he was a commercial telegraph; it was used as a guideline for vessels sailing on the Douro River; it served to raise a flag when the ship "paquete" arrived so that the traders knew of its approach; it was a strategic point for military and political combat; and today it is undoubtedly one of the most important tourist attractions in the city of Porto