User: Write a brief paragraph about the evolution of Egyptian pyramids.
Assistant: Egyptian pyramids are fascinating ancient buildings edified more than 2500 years before the Common Era. According to Egyptologists, these megalithic structures served as tombs for the biggest pharaohs that successively ruled the region in that Era. The biggest ones, present until now in Giza, are built with astonishing precision using the rudimental tools and materials that were available at that time. For example, Khufu pyramid, culminating at 481 feet, is an architectural masterpiece. The size, orientation and precision of this pyramid are keeping the best current architects agape. However, the journey was not straightforward for ancient Egyptians. Building such megalithic structures remains very hard to even nowadays. Before achieving the precision of the pyramids on Giza plateau, some inconsistencies and simpler trials are still present in Egypt showing the progressive improvement in their construction know-how through time. The first historically documented pyramid in Egypt is attributed to Djozer pharaoh in the third dynastic period. It is a stepped structure with superposed squares without big attention to the external design and polishment that we find later in the more recent pyramids. Egyptologists proved the existence of many other attempts to build similar structures in the same dynasty. However, the first complete pyramid structures appeared only in the 4th dynasty, giving successively the rise of the great pyramids of Meidum, Dahshur, and Giza