The purpose of the building called the giparu, built and rebuilt from possibly as early as Early Dynastic times down to the Neo-Babylonian period, was to serve as the official dwelling of the entu-priestess. This is clearly stated by the entu Enanedu herself. She describes herself as “patroness who had the giparu built for its entu office on the sacred site “, and speaks of the giparu as “my abode of the entu-ship”. King Nabonidus who rebuilt the giparu for the last time records on bricks that, “for Sin, my lord, I built the giparu-temple, the house of the entu-priestess.”
The entu living in the giparu was a priestess of the highest order, elected by the god Nanna and revealed to the country through omens. So important was the office that the priestess was always of royal blood, the daughter or sister of the king. Ninmetabarri, daughter of AN.BU, king of Mari, whose inscribed calcite cup was found at Ur, may be the first entu of Nanna who has left any written record of herself. Enanedu spoke of herself as daughter of Kudur-Mabuk, sister of Warad-Sin; and Nabonidus, who revived the office of entu after hundreds of years of oblivion, established his daughter Ennigaldi-Nanna as entu in Ur after learning through lengthy divination that she was Nanna's choice. The importance of the office of entu is further stressed by the evidence that the kings occasionally named their regnal years after the appointment and the installation of the entus.