It serves as the seat of the executive power and the Secretariat of Governance of the State.

Its name comes from its former owner, Don Juan Martínez de Aguayo, who bought the property in 1644 and used it as a place to store grains and was also occupied by pigs.

The splendid construction stands out for its harmonious dimensions. The monumental building consists of a courtyard and its central fountain, delimited by double arcades made of gray stone.

It was the seat of a college that was under the Jesuits' control until their expulsion in 1767. In 1790, it became part of Colegio Carolino. Later, the building served various purposes, such as a school, military barracks, and warehouse for a brewery. In 1967, the state government rescued the building and established its central offices there.

Despite the modifications made, the façade still retains elements from the 17th century, such as the arches and the fountain.