The Great Pyramid of Cheops (the Pharoah otherwise known as Khufu) was built at Giza, Egypt, some 4,500 years ago, and was, for thousands of years, the tallest man-made structure in the world at 481 feet high.
Most of the structure consists of limestone blocks, with some of the internal material being granite. The limestone blocks, more than 2 million of them, each weigh 2.5 tons and are all the same size, fitting together with a tolerance of less than 2 millimetres.
Given that the Pyramid took 20 years to build, that would mean that an average work schedule would have involved the addition of some 400 blocks a day.