Is the only arch of the four that aforetime existed in the square which is conserved. It was used by the nobles of the palace to move through the various departments of the edifice, or to access the privately part the they owned in the church of San Benito.
In 1843, the decision to demolish these archs is taken because it said that they interrupted the passage of the weekly market, celebrated in this location, as well as people that traveled by horse and carriages full of wood. The responsible of this decision was Javier de Zárate y Murga, Marquis of Montesacro.