Hidden in the volcano that makes up the entirety of the island, accessed by descending into the magma pit of the volcano, and outside of where Atlas, Alara, and Herk fought–telepathically–and the “Cookie God“ was eaten.

After having washed ashore on the island, Alara–the Eladrin Spellforger– met Atlas and Herk who had traveled here, with Remor/Apollo, in search of Vophon the God of Time to explain a prophecy they’ve heard about. They eventually make their way into the volcano and find an endless library of names and books and in the center, a well of some kind.
Herk looked through their book and Vophon granted them visions of other worlds where they had all died at the Elven Kingdom, and worlds where Euriem and Hyperion might have lived.
Eventually the three gathered around the well in the library’s center, where a telepathic battle ensued between Aatrox–Atlas’s Patron– Herk and Alara that culminated in Herk making a pact with Aatrox as well so Alara and their friends would not be harmed.