The Great Pyramid is one of the most famous landmarks in the world. Scientists have been studying it for centuries, and many today are still working to uncover its secrets. Did the ancient Egyptians use stars to guide how the Great Pyramid was built? What was the purpose of the two mysterious narrow shafts extending from the King's Chamber to the outside walls? And how did workers move the massive limestone blocks into place? One thing is certain: even after thousands of years, this remarkable ancient Egyptian structure remains one of the greatest achievements of humankind.