The square seems to owe its name to an old inn, one of several that existed, in which colts and mules were sold. In fact, the square was originally conceived as a totally enclosed quadrangular space, perhaps so that the animals would not escape, and not rectangular and open as it is now. However, the name of the square may be due to the spirited potro – or colt -- that adorns the top of the central fountain . The fountain dates to 1577, and was built with the aim of improving the water supply in this area of the city. The water that supplied both this fountain and the one that no longer exists in Plaza de la Corredera, was supplied by water transported from the outskirts of the city by an ancient Roman aqueduct from the time of Emperor Augustus. Today the water is still drinkable, so if you are visiting Cordoba in its hot summer, feel free to cool off!