The Great Pyramid of Khufu at Giza is a large funerary structure from Egypt's Old Kingdom. It contains passages and burial chambers, but the bulk of the building consists of vast quantities of stone.

It originally had a smoother outer casing, most of which is now missing. Measurement and archaeology continue to investigate its construction and internal structure.

Materials

The Great Pyramid consists of an estimated 2.3 million blocks. Approximately 5.5 million tonnes of limestone, 8,000 tonnes of granite, and 500,000 tonnes of mortar were used in the construction.

Most of the blocks were quarried at Giza just south of the pyramid, an area now known as the Central Field. They are a particular type of nummulitic limestone formed of the fossils of prehistoric shell creatures, whose small disc form can still be seen in some of the pyramid's blocks upon close inspection. Other fossils have been found in the blocks and other structures on the site, including fossilized shark teeth. The white limestone used for the casing was transported by boat across the Nile from the Tura quarries of the Eastern Desert plateau, about 10 km (6.2 mi) south-east of the Giza plateau. In 2013, rolls of papyrus called the Diary of Merer were discovered, written by a supervisor of the deliveries of limestone from Tura to Giza in the 27th year of Khufu's reign.

The granite stones in the pyramid were transported from Aswan, more than 900 km (560 mi) south. The largest, weighing 25 to 80 tonnes, form the ceilings of the "King's chamber" and the "relieving chambers" above it. Ancient Egyptians cut stone into rough blocks by hammering grooves into natural stone faces, inserting wooden wedges, then soaking these with water. As the water was absorbed, the wedges expanded, breaking off workable chunks. Once the blocks were cut, they were carried by boat on the Nile to the pyramid and used a now dry offshoot of the river to transport blocks closer to the site.

Workforce

The ancient Greeks believed that slave labour was used, but modern discoveries made at nearby workers' camps associated with construction at Giza suggest that it was built by thousands of conscript labourers.

Worker graffiti found at Giza suggest haulers were divided into zau (singular za), groups of 40 men, consisting of four sub-units that each had an "Overseer of Ten".

As to the question of how over two million blocks could have been cut within Khufu's lifetime, stonemason Franck Burgos conducted an archaeological experiment based on an abandoned quarry of Khufu discovered in 2017. Within it, an almost completed block and the tools used for cutting it had been uncovered: hardened arsenic copper chisels, wooden mallets, ropes and stone tools. In the experiment replicas of these were used to cut a block weighing about 2.5 tonnes (the average block size used for the Great Pyramid). It took four workers 4 days (with each working 6 hours a day) to excavate it. The initially slow progress sped up six times when the stone was wetted with water. Based on the data, Burgos extrapolates that about 3,500 quarry-men could have produced the 250 blocks/day needed to complete the Great Pyramid in 27 years.

Interior

The internal structure consists of three main chambers (the King's, Queen's and Subterranean Chambers), the Grand Gallery and various corridors and shafts. None of the interior walls were decorated or inscribed, as was the norm for tombs of the 4th dynasty, apart from the marks and names of work-gangs left on blocks of the relieving chambers.

There are two entrances into the pyramid: the original and a forced passage, which meet at a junction. From there, one passage descends into the Subterranean Chamber, while the other ascends to the Grand Gallery.

Both the King's and Queen's Chamber have a pair of small "air-shafts". Above the King's Chamber are a series of five relieving chambers.