Borromini's Perspective Gallery

Inside the courtyard of Palazzo Spada near Campo de' Fiori, Baroque architect Francesco Borromini designed a nine-metre corridor that appears nearly four times its actual length. The trick: the floor rises, the ceiling drops, the columns shrink, and the walls converge, creating a forced-perspective illusion so convincing that the statue at the far end — which looks life-sized and 37 metres away — is actually 60 centimetres tall and less than nine metres from you. It's a 30-second visual trick that reveals something profound about Baroque ambition: the willingness to reshape reality itself through architecture. The palazzo also houses a small but quality painting collection (Borromini's rival Bernini is, deliciously, not represented).