A Chankiri Tree. The sign reads "Chankiri Tree against which executioners beat children"
A Chankiri Tree or Killing Tree was a tree in the CambodianKilling Fields against which children and infants were smashed because their parents were accused of crimes against the Khmer Rouge. It was so the children "wouldn't grow up and take revenge for their parents' deaths". Some of the soldiers laughed as they beat the children against the trees. Not to laugh could have indicated sympathy, making oneself a target.