In Flanders fields the poppies blow
Between the crosses, row on row,
That mark our place and in the sky,
The larks, still bravely singing, fly,
Scarce heard amid the guns below.

 This refers to the site of the mass grave at Flanders Fields where the thousands of soldiers who died fighting the second battle of the Ypres were buried. 
 There is a gentle, rocking rhythm in the stanza, but particularly in this line.