We know intuitively when a place is in flow. It strikes a balance between boredom and overstimulation through, for instance, combining monuments with background buildings, defamiliarizing features with familiar ones, and a wide range of people and activities. It is not the unrelenting grid, but nor is it deconstructivism on the urban scale. Places in flow also allow ease of movement of people, goods, and information. Too much ease of movement would produce boredom and stasis, eliminating mystery and wonder, ultimately the Achilles heel of the modern city. Places that are truly in flow thus have interesting and unexpected detours and zigzags. We might call these ebbs or the rocks around which the flowing stream navigates.3 Because people require varying amounts of stimulation to be in flow, places that are in flow offer choice and may be experienced in different ways.