The Golden Harp was one of the Things of Power, and played to wake The Sleepers, Oldest of the Old. The harp is obtained by the Light in The Grey King in order to wake the Sleepers in preparation for the final battle. Whoever plays the harp has the protection of the High Magic. The Golden Harp was put in Wales, under the Birds' Door, and was protected by a Lord of the Dark, Merriman Lyon and King Arthur. Only the youngest of the Old Ones and Bran could have the Golden Harp. At the end of The Grey King, the Harp was put in a lake by Caradog Prichard.
In the Great Hall where the Golden Harp was kept, there were also the second of the three Golden Shields.