Great Pyramid of Giza

 The Great Pyramid of Giza (also called the Pyramid of Khufu and the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza Necropolis bordering what is now El Giza, Egypt. It is the oldest of the Seven Wonders of the Ancient World, and the only one to remain largely intact. Egyptologists believe that the pyramid was built as a tomb for fourth dynasty Egyptian Pharaoh Khufu[1] (Cheops in Greek) and constructed over a 14 to 20-year period concluding around 2560 BC. Initially at 146.5 metres (480.6 ft), the Great Pyramid was the tallest man-made structure in the world for over 3,800 years, the longest period of time ever held for such a record. Originally, the Great Pyramid was covered by casing stones that formed a smooth outer surface; what is seen today is the underlying core structure. Some of the casing stones that once covered the structure can still be seen around the base. There have been varying scientific and alternative theories about the Great Pyramid's construction techniques. Most accepted construction hypotheses are based on the idea that it was built by moving huge stones from a quarry and dragging and lifting them into place.


There are three known chambers inside the Great Pyramid. The lowest chamber is cut into the bedrock upon which the pyramid was built and was unfinished. The so-called[2] Queen's Chamber and King's Chamber are higher up within the pyramid structure. The Great Pyramid of Giza is the only pyramid in Egypt known to contain both ascending and descending passages. The main part of the Giza complex is a setting of buildings that included two mortuary temples in honor of Khufu (one close to the pyramid and one near the Nile), three smaller pyramids for Khufu's wives, an even smaller "satellite" pyramid, a raised causeway connecting the two temples, and small mastaba tombs surrounding the pyramid for nobles.



It is believed the pyramid was built as a tomb for fourth dynasty Egyptian pharaoh Khufu[1] and constructed over a 14-[3] to 20-year period.[clarification needed] Khufu's vizier, Hemon, or Hemiunu, is believed by some to be the architect of the Great Pyramid.[4] It is thought that, at construction, the Great Pyramid was originally 280 Egyptian cubits tall, 146.5 metres (480.6 ft) but with erosion and absence of its pyramidion, its present height is 138.8 metres (455.4 ft). Each base side was 440 royal cubits, 230.4 metres (755.9 ft) long. A royal cubit measures 0.524 metres.[5] The mass of the pyramid is estimated at 5.9 million tonnes. The volume, including an internal hillock, is roughly 2,500,000 cubic metres.[6] Based on these estimates, building this in 20 years would involve installing approximately 800 tonnes of stone every day. Similarly, since it consists of an estimated 2.3 million blocks, completing the building in 20 years would involve moving an average of more than 12 of the blocks into place each hour, day and night.



The Great Pyramid consists of an estimated 2.3 million limestone blocks with most believed to have been transported from nearby quarries. The Tura limestone used for the casing was quarried across the river. The largest granite stones in the pyramid, found in the "King's" chamber, weigh 25 to 80 tonnes and were transported from Aswan, more than 500 miles away. Traditionally, ancient Egyptians cut stone blocks by hammering wooden wedges into the stone which were then soaked with water. As the water was absorbed, the wedges expanded, causing the rock to crack. Once they were cut, they were carried by boat either up or down the Nile River to the pyramid.[18] It is estimated that 5.5 million tons of limestone, 8,000 tons of granite (imported from Aswan), and 500,000 tons of mortar were used in the construction of the Great Pyramid.[19]



The Great Pyramid is surrounded by a complex of several buildings including small pyramids. The Pyramid Temple, which stood on the east side of the pyramid and measured 52.2 metres (171 ft) north to south and 40 metres (130 ft) east to west, has almost entirely disappeared apart from the black basalt paving. There are only a few remnants of the causeway which linked the pyramid with the valley and the Valley Temple. The Valley Temple is buried beneath the village of Nazlet el-Samman; basalt paving and limestone walls have been found but the site has not been excavated.[32][33] The basalt blocks show "clear evidence" of having been cut with some kind of saw with an estimated cutting blade 15 ft in length capable of cutting at a rate of 1 1/2 inches (40 mm) a minute. John Romer suggests this "super saw" may have had copper teeth and weighed up to 300 lbs. He theorizes such a saw could have been attached to a wooden trestle and used in conjunction with possibly vegetable oil, cutting sand, or emery or pounded quartz to cut the blocks and would have required at least a dozen men to operate it.[34]