Built from 1548 by Cardinal Girolamo Capodiferro (1502-1559) on pre-existing buildings owned by the family, it was almost completely completed in the Jubilee of 1550, including the stucco decorations that embellish the façade and the courtyard, In the following century, the palace passed to Cardinal Bernardino Spada (1594-1661), who, from the moment of purchase, began a series of works that lasted thirty years and gave the complex a new and more pleasant appearance. The tour of the first floor ends with a visit to the Secret Garden, home to Rome's most spectacular Baroque work of art, the Illusionistic Colonnade (or Perspective), created in 1653 by Francesco Borromini for Cardinal Bernardino Spada. A sophisticated moral warning to those who put too much faith in the appearance of the world, the Colonnade deceives the viewer with dimensions that are actually very different from how they are perceived by the eye, being the skillful product of mathematical and perspective calculations.