House of the Mírdain

The guildhouse of the brotherhood of the Jewelsmiths of Eregion, in which were the workshops and the treasuries of the guild. It was here that Sauron, in his guise as Annatar, guided Celebrimbor and his smiths in the making of the Rings of Power, and aided them in creating the Seven Rings and the Nine. When Sauron left Eregion in about the year II 1500, Celebrimbor continued to work, creating the Three Rings in the smithies of the House of the Mírdain, and it was through these Three Rings that he discovered the treachery of Sauron and the existence of the One Ring.

With his plan to dominate the Elves revealed, Sauron went to open war, setting out to recover the Rings of Power by force. In II 1695 he invaded Eriador, overcoming all opposition to march into Eregion. A desperate Celebrimbor fought Sauron himself on the steps of his House, but he was defeated and Sauron entered the halls of the Gwaith-i-Mírdain. He thus recovered the Nine Rings, and discovered the whereabouts of the Seven, though the Three had already been taken beyond the Dark Lord's reach.