In this article, Engineer Alberto Donini presents an innovative method, the “Relative Erosion Method” (REM), which he developed to determine the construction date of ancient structures. He applies this method to the Khufu pyramid on the Giza Plateau. Is it possible that the current archaeological dating of this ancient Egyptian monuments is incorrect? Is it also possible that the alternative dates proposed by various researchers are likewise incorrect? To address these questions, the author analyses the Khufu pyramid from an unconventional perspective in order to determine the most probable period of its construction. The REM is based on the ratio between two types of erosion affecting the same type of rock in the same location: one with a known date and the other with a date to be determined. This ratio is then used to calculate the age of the stone block under examination.