The Cerddi is a significant elvish text, something akin to the holy writing of Seren. It is mentioned briefly in several of the books found in Lletya, and was written by Ceidwad on Tarddiad. The Cerddi is believed to contain the knowledge of Seren, ranging from the nature of elven crystal to the history of the elves since they arrived through the World Gate in the First Age. The only known part of the Cerddi appears in the great divide: