Not only these play a religious activity but also had entrusted civil functions, the result of linking the temples of San Salvador and Santa Cruz with the City Hall of Madrid.
Both towers excelled in its front two separate municipal coats of arms, which reported that direct link with the Council.
The call for municipal meetings was done through the bell tower, which also had the task of marking the curfew (at nine in winter and an hour later in summer), when the situation required it.
The tower, in particular, rose between 1627 and 1680 from a design by the architect Francisco del Castillo, who devised a solution of four bodies, quadrangular and Herrerian spire with roof lantern, as can be seen in the detail of the plan of Teixeira.
Like the Atalaya de la Villa, it have installed a clock and its bell served to summon the council, because in the church of Santa Cruz it occasionally met the Chamber of Mayors to celebrate their festivals.