The Pyramid of Chefren (or Khafre)in front, the Pyramid of Cheops (or Khufu)at the back.
Although Chefren seems to be the bigger of the two;
Cheops is actually 3 meters higher (originally 146.5 meters vs 143.5 meters),
and at the base 15.5 meter wider (originally 230 meters vs 214.5 meters).