LONDON — A lawn at the Olympic Park in London has taken on the appearance of a mass, open-air graveyard, with tens of thousands of shrouded figures laid out in neat rows — one of Europe’s many commemorations of this weekend’s centennial of the end of World War I.

The figures, each the size of a child’s doll, make up an art installation called “Shrouds of the Somme” that went on display at the park on Thursday, symbolizing the 72,396 British and Commonwealth servicemen who died on the Somme battlefields in France from 1916 to 1918 and who had no known graves.

The British artist Rob Heard spent five years hand-sewing calico shrouds to the thousands of small figures so that the bodies of the soldiers could symbolically be laid to rest on British soil in time for the anniversary on Sunday of Armistice Day.