document: Light installations have been placed at locations around the city including Piccadilly, Mayfair, King's Cross, Trafalgar Square and Westminster.
  Lumiere London runs from 18:30 GMT to 22:30 on Saturday and Sunday.
  The art installations include a life-size 3D elephant, human figures floating in the sky, giant fish, LED stickmen and stars.
  The festival has been developed by creative producers Artichoke.
summary: London has been illuminated by its first festival of light, featuring 30 artists.