New York feels like a city of right angles and hard edges. When I picture London or Paris, they appear to me in my mind as  a series of interlocking curves and roundabouts. Berlin's neighborhoods feel like little intertwined nests. Seoul is a sprawling city of wide avenues that contain little honeycombed alleys hidden inside. North American cities tend to be made in grid patterns but this is especially true of New York whose grid extends vertically as well. Square and rectangular buildings rise up around you and slice the sky with clean lines. The effect is felt visually but also carries over into the spirit of the place. If you don't manage to wedge yourself into the right spaces, those corners are sharp.