A pyramid is a three-dimensional geometric shape with a polygonal base and triangular faces that converge at a single point called the apex. The most famous pyramids are the Egyptian pyramids, which were built as tombs for pharaohs. These structures are known for their impressive size and precise construction. Pyramids can be found in various cultures around the world, including the Mesoamerican pyramids built by the Maya and Aztec civilizations. They often served religious or ceremonial purposes. The shape of a pyramid allows for stability and strength, making it a popular architectural design throughout history.