It is where the ancient Star Harvester is located within the larger and taller pyramid.
Revenge of the Fallen film
As the battle between Autobots aided by N.E.S.T. forces and Decepticons in a village, Devastator had climbed up the pyramid and dug the top to excavate the harvester but was interrupted and destroyed by a prototype laser railgun fired by U.S.S. Kidd with coordinates provided by Simmons.
But half thanks to Devastator, the harvester was already half excavated and The Fallen used it to absorb the Sun. However, Jetpower Optimus Prime had destroyed the harvester and engaged Megatron and The Fallen.
After the battle, the Pyramids were in ruins.