This magical site was located within the ancient halls of Castle Grayskull on Eternia and served as a repository of power within the fortress. It was protected site that was guarded by a woman that held the position of the Sorceress of Castle Grayskull. At some point in the past, the Sorceress of Kuduk Ungol who maintained a long life as custodian of the Castle. But eventually she grew old and desired a replacement before she passed away. It was then that a young woman known as Teela Na came searching for Castle Grayskull in order to save her village from the threat of the wizard Morgoth. Ungol allowed Teela Na entry and told her that she could get the power she needed to save her village but at the price of becoming the new Sorceress of Castle Grayskull. Teela Na accepted and the trial began as she entered into the Pool of Power in order for the fortress to determine if she was worthy of the role. Castle Grayskull ultimately accepted her and infused Teela Na with magic thus transforming her into her falcon form; Zoar which began her new role as the Sorceress of Castle Grayskull.