A great many cities are experiencing difficulties which are nothing new in the history of cities, except in their scale. Some cities have lost their original purpose and have not found new one. And any large or rich city is 31 going to attract poor immigrants, who flood in, filling with hopes of 32 prosperity which are then often disappointing. There are backward towns on the edge of Bombay or Brasilia, just as though there were on the edge of 33 seventeenth-century London or early nineteenth-century Paris. This is new is 34 the scale. Descriptions written by eighteenth-century travelers of the poor of Mexico City, and the enormous contrasts that was to be found there, are very 35 dissimilar to descriptions of Mexico City today—the poor can still be numbered 36 in millions. The whole monstrous growth rests on economic prosperity, but behind it 37 lies two myths; the myth of the city as a promised land, that attracts immigrants 38 from rural poverty and brings it flooding into city centers, and the myth of the 39 country as a Garden of Eden, which, a few generations late, sends them 40 flooding out again to the suburbs.