The Borromini Gallery is located into the courtyard of Palazzo Spada. Borromini created the masterpiece
of a false perspective in the arcaded courtyard of Palazzo Spada, in which diminishing rows of columns
and a rising floor create the optical illusion of a gallery 37 meters long (it is only 8 meters!) with a lifesize
sculpture in daylight beyond: the sculpture is 60 cm high. Borromini was aided in his perspective trick by a mathematician.