Henry Wadsworth Longfellow

White swan of cities, slumbering in thy nest
  So wonderfully built among the reeds
  Of the lagoon, that fences thee and feeds,
  As sayeth thy old historian and thy guest!
White water-lily, cradled and caressed
  By ocean streams, and from the silt and weeds
  Lifting thy golden filaments and seeds,
  Thy sun-illumined spires, thy crown and crest!
White phantom city, whose untrodden streets
  Are rivers, and whose pavements are the shifting
  Shadows of palaces and strips of sky;
I wait to see thee vanish like the fleets
  Seen in mirage, or towers of cloud uplifting
  In air their unsubstantial masonry.