The Great Pyramid of Giza took between 20 and 30 years to build. It was built for the Pharaoh Khufu and was finished in about 2560 BCE, making it over 4,500 years old. It is near two other Pharaohs' pyramids, as well as being part of its own complex, with three smaller pyramids for Khufu's wives.
The construction of the Great Pyramid of Giza is a subject of much debate and speculation by historians. It was a remarkable feat of engineering for the time, requiring the moving and placement of around 2.3 million limestone blocks, each weighing around 5,500 pounds. The logistics of building such a structure at the time, the tallest man-made structure in the world for 3,800 years, are what cause such debate. The ancient Egyptians lacked any powered moving equipment, and so had to rely on human labor for all the moving and placement.
It is thought that the pyramid took the work of 20,000 to 100,000 laborers. Even with so many workers, the task required sophisticated planning and tool use. Different theories propose the use of levers, wood sleds or long ramps to move the stones into place. Each of these theories has its problems. For instance, for a ramp to help bring a block to the top of the pyramid at a plausible angle, it would have to be a mile long.