Obelisks were a prominent part of the Ancient Egyptian architecture, placed in pairs at the entrances of various monuments and important buildings such as temples. In 1902, "Encyclopædia Britannica" wrote: "The earliest temple obelisk still in position is that of Senusret I of the XIIth Dynasty at Heliopolis (68 feet high)". The word "obelisk" is of Greek rather than Egyptian origin because Herodotus, the great traveler, was the first writer to describe the objects. Twenty-nine ancient Egyptian obelisks are known to have survived, plus the Unfinished obelisk being built by Hatshepsut to celebrate her sixteenth year as pharaoh. It broke while being carved out of the quarry and was abandoned when another one was begun to replace it. The broken one was found at Aswan and provides the only insight into the methods of how they were hewn.