The document discusses the pyramids of Egypt, including how and why they were built. It explains that the oldest pyramids were step pyramids built in 2630 BCE for Pharaoh Djoser. The pyramids were built by Egyptians, including willing workers, to protect the body and possessions of the Pharaoh after death. The largest pyramid, the Great Pyramid, was built around 2550 BCE and was the world's tallest structure for nearly 4,000 years. The document also briefly mentions the Bent Pyramid and provides information about obelisks constructed by the Egyptians.