Three giant pyramids stand at Giza, near Cairo. The biggest one is the Great Pyramid, which was built as the tomb of a king named Khufu. When it was new, it was about 481 feet tall; it has more than two million stone blocks, and an average block weighs about 2.5 tons. Each pyramid is thought to be the tomb of the king who ordered it built. Khufu's is the biggest of the three.

Where did all that stone come from? The smooth white outer stone was limestone from a quarry at Tura. The quarry was on the Nile's east bank, about 8 miles away. The cut blocks were likely placed on sledges and pulled by teams of men or cattle. About a dozen men pulled a sledge that held a 2-ton block. Most researchers agree that building the pyramids used ramps of some kind. They argue about what shape the ramps took. That is one of the open puzzles of the pyramids.

Then there is the question of who did the work. Egyptian workers built the pyramids, not slaves. Many were young men from farming villages. They worked in crews that took turns. Some crews had team names, such as "Friends of Khufu" and "Drunkards of Menkaure." Workers were hired and paid. Egypt had no money then, so pay came in food, such as grain. Communities across Egypt probably sent workers and supplies too.

Diggers found proof of the workers' lives near the pyramids. They found a workers' town with bakeries. Bread was baked there in big bell-shaped clay pots. Khufu began his pyramid around 2550 B.C. King Djoser had a step pyramid built for his tomb at Saqqara. It was made of stacked levels, each a little smaller than the one beneath it. The three Giza pyramids came from three generations of kings: Khufu, his son Khafre, and a later king, Menkaure.

Beside the pyramids sits the Sphinx. It is a huge statue with the body of a lion and the head of a pharaoh. It is about 240 feet long and more than 65 feet tall. For most of its life, desert sand buried it, sometimes up to its shoulders. Many people say that Napoleon's soldiers shot off its nose. That is not true; a drawing made in 1737 already shows the nose destroyed. An Islamic source reported that the nose was removed in the late 14th century.

Words to know

• limestone: soft stone
• quarry: stone pit
• sledges: sleds
• ramps: sloped paths
• Sphinx: lion statue