This book investigates the historical, architectural, and mathematical mysteries surrounding the Great Pyramid of Cheops. Peter Tompkins, an author known for his interest in historical enigmas, synthesizes centuries of exploration, surveying data, and speculative theory to argue that the pyramid served as a sophisticated instrument for measuring the Earth's dimensions and celestial alignments. The text relies on a combination of historical accounts from early explorers and the findings of modern researchers to challenge conventional archaeological interpretations.

Readers frequently note the dense, historical nature of the prose and the author's commitment to fringe theories that deviate from standard Egyptological views. Experts often categorize this as a foundational text for those interested in alternative history and the history of pyramid research, though they caution that the scientific claims should be evaluated against modern archaeological evidence.