Pyramids are distributed in Egypt and the Americas， including upper Egypt
middle Egypt and lower Egypt in ancient Egypt， present-day Sudan and Egypt.
There are about 80 pyramids scattered in the lower reaches of the Nile. Among them.
The largest one is the Houf Pyramid， which is 146.5 meters high and 230 meters long at the bottom.
It is made of 2.3 million stone blocks with an average area of 2.5 tons each， covering 52，000 square meters.
