This article contains plot details from the latest book.
Siren Rock is a place where most elves go in order to bottle starlight, according to Dex in the first book. He takes Sophie to Moonglade because he says it is much less crowded. Not much is known about this place. Siren Rock is later mentioned in Everblaze, as it is where Sophie and Fitz go to bottle Quintessence in order to make Fryssin, so they can put out the Everblaze that Fintan caused at his healing, killing Kenric and hurting others in the process.