The El Arenal district was closed off at the Torre del Oro (Tower of Gold) by a section of wall that connected it to the Torre de la Plata (Tower of Silver). This formed part of Seville's city walls, built to protect the Royal Alcázar. It seems the name Torre del Oro is derived from the golden reflections produced by the tiles that used to adorn its walls. Ships that were about to embark on expeditions across the globe were prepared and loaded in the tower's shadow.