In spite of the wealth of examples of urban architecture in older cities, both in Europe and in the United States solutions to current problems of the physical decay of cities in the United States have come slowly. The first reaction after the war was to bulldoze and build bright new towers and efficient roadways, but these solutions did not respond to people By the close of the 1960's it became more common to deal gently with the' existing' urban fabric and to insert new buildings in such a way as to complement the physical and social environment; in other cases valued buildings have been rehabilitated and returned to economic productivity. A particularly striking example is the rehabilitation of Ghirardelli Square, San Francisco. This, hillside mélange of nineteenth-century commercial buildings clustered around a chocolate plant, was purchased in 1962 by William Roth to forestall wholesale development of the waterfront as a district of high-rent apartment towers. Nearly all of the nineteenth-century buildings were retained and refurbished, and a low arcade was added on the waterside. There are several levels, dotted with kiosks and fountains, which offer varied prospects of San Francisco Bay. Perhaps most telling is the preservation of the huge Ghirardelli sign as an important landmark; it is such improbable, irrational, and cherished idiosyncrasies which give cities identity and character.