Gateway Arch Source/credit: JakeHuberMedia What am I looking at? The Gateway Arch in St Louis is an optical illusion. The arch is as tall as it is wide; 192 meters. But from nearly every angle it will seem much taller than it is wide. And you can’t really see the arch head-on when standing on the ground. More optical illusions:Broken ChairHovering CarMan BunEyeglassesFloating either wayApartment on fireFlying F1 CarFeeling deflated