Towns and Cities

urbanisation, UN (United Nations), Third World, Developing or Emerging Countries, rural areas, ancient ancestors, waterways, Nile, Tigris and Euphrates basin, tumbling down, stagnated, hygiene problems, sewage, cholera, diarrhoea, slums, steam engine, big boost, metropolis, exponential growth, third boom, mass exodus, limit the scope for growth, getting out of hand, pools of human misery, flocking into, to eke out a living, trapped in the cycle of urban degradation, unrest, disease, coups, flood of refugees, pristine environment