how long did it take to build the khufu pyramid
Great Pyramid of Giza Based on a mark in an interior chamber naming the work gang and a reference to the fourth dynasty Egyptian Pharaoh Khufu, Egyptologists believe that the pyramid was built as a tomb over a 10- to 20-year period concluding around 2560 BC. Initially at 146.5 metres (481 feet), the Great Pyramid was the tallest man-made structure in the world for more than 3,800 years. Originally, the Great Pyramid was covered by limestone 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.
Timbuktu During its twelfth session, in December 1988, the World Heritage Committee (WHC) selected parts of Timbuktu's historic centre for inscription on its World Heritage list.[59] The selection was based on three criteria:[60]
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National World War II Memorial Ground was broken in September 2001. The construction was managed by the General Services Administration.