The Egyptian pyramids are the oldest stone buildings in the world, built nearly 5000 years ago. They are among the world's largest structures, with the biggest one taller than a 40-story building. More than 80 pyramids still stand today, containing secret passageways, hidden rooms, and false doors. Built for kings (Pharaohs) to protect their bodies after death, the pyramids are a symbol of ancient Egyptian beliefs and architecture. The construction of pyramids required thousands of workers and intricate planning. The Great Pyramid of Giza, the largest of the three Giza pyramids, stands at 480 feet tall and was built for Pharaoh Khufu.