The three largest pyramids in Egypt’s Giza – the pyramids of Cheops, Chephren and Mykerinos – date from the Old Kingdom and were built over 4,500 years ago. They are the tombs of the next pharaohs of the 4th Dynasty. The largest and the oldest of them is the Cheops pyramid, originally 147 meters high (today, as a result of erosion and deposition, it is only 138.8 meters). By analogy, the pyramid of Khafre, once rising to a height of 143.5 meters, today is only 136 meters, and the pyramid of Mykerinos 62 meters (originally 65).
The Pyramids of Cheops and Khafre are therefore much taller than many much younger buildings such as London’s famous Big Ben.