A building from the second third of the 18^th century, built as the residence for the archbishop and cardinals of the Archdioceses of Madrid, besides housing other ecclesiastical offices. Located in the Latin Quarter, it is simple and barely decorated, with the exception of some parts like, for example, the doorway located in Pasadizo del Panecillo (Bread roll passage), next to the Papal Basilica of San Miguel, which is without a doubt its most artistic element. It has traits of Madrid Baroque, such as its characteristic curves.

The building is built on three and four storeys (depending on the uneven ground level) and has attic roofs. The façades are covered with mortar, except for the plinths, which are granite. In the interior, there is an important collection of works of art. One of the most noteworthy, the 18th-century chest where the mortal remains of St Isidro are kept, was moved to the Almudena Cathedral in 1993 when this temple opened its doors.