Penetration illusions are optical phenomena where an object appears to pass through another solid object, creating a visual deception of depth and transparency. These illusions exploit principles of perception such as figure-ground organization and Gestalt psychology, manipulating the way our brains interpret visual information. Examples include the famous “Penrose stairs” and “impossible objects” like the Penrose triangle, challenging our understanding of spatial relationships. Penetration illusions have been studied in cognitive psychology and art to understand how humans perceive and interpret visual stimuli, shedding light on the intricacies of visual processing. Artists and designers often use these illusions to create mind-bending artwork that plays with viewers’ perceptions, showcasing the fascinating intersection of art, science, and cognition.