A pyramid is a structure with a square or rectangular base and four triangular sides that meet at a point at the top. Pyramids have been built by many ancient civilizations, including the Egyptians, Aztecs, and Mayans. They were often used as tombs for kings and queens, and were often decorated with hieroglyphs and symbols. Pyramids are also used in modern architecture, such as the Louvre in Paris and the Luxor Hotel in Las Vegas. Pyramids are a symbol of strength and stability, and are often used to represent power and wealth.