A memorable place often occupies an important feature in the landscape: a harbor, a bay, a river delta, a lake, a hill within a town -- a physical event in the natural environment. We remember places that are dignified by a unique interaction between the man-made and the natural, places like Naples by the bay, Geneva at the lake's end, Rome on the Tiber's bend, Cape Town with Table Mountain, Amsterdam and its canals, or Ronda, Spain, a city bridging between two cliffs. Not only are these places set in special points in the landscape, but their own construction often amplifies their surroundings: an alignment of buildings on the watershed to overlook views ( Jerusalem), buildings that contain the curve of a harbor (Cannes), an important bridge to cross a river (the Ponte Vecchio). Great urban streets frequently maintain specific relationships to the natural terrain ( Barcelona's Ramblas descending to the bay) and link the most intense urban activity with great parks and gardens ( Fifth Avenue in New York City, the Champs Elysées in Paris, or Regent Street in London).
What we recognize as the special character of a city is the synthesis of an identifiable spatial structure with the unique mysteries and secrets of its site. As we know, many urban centers share the same generic diagram (a grid or radiating