Stephen Wiltshire is the subject of this week's Friday Afternoon Moment of Whimsy. He is described thus: "[A] British man who was diagnosed as autistic when he was a child. He's also been noted for his exacting memory, which allows him to recreate (in drawings) vast scenes he sees only once. This video shows his 16-foot-panorama of Rome after taking one helicopter ride above the city... He gets every detail right, down to the number of windows in each building."

He begins his magnum opus at... where else?