Since Monday, Oct. 26, British artist Stephen Wiltshire has been filling in an 18-foot canvas at the Pratt Intitute in Brooklyn as he attempts to draw the entire Manhattan skyline from memory. Diagnosed with autism at the age of three, Wiltshire has an unusually powerful photographic memory that he has applied to rendering cityscapes, including London, Tokyo, Hong Kong, Rome, Madrid, Frankfurt, Dubai and Jerusalem.

The drawing is expected to be completed by Friday (you can follow his progress via live webcam on his website). Wow.