Monumenta Elforum

It can be purchased from the Scoia'tael merchant south of Novigrad and can be found as loot in only 2 locations - in Mad Kiyan's room during Scavenger Hunt: Cat School Gear, and (guaranteed due to a randomization bug) in the Kaer Morhen room occupied first by Yennefer and then Avallac'h. The chest that has it there only appears at the start of The Battle of Kaer Morhen though.

Journal entry[]

To my beloved Y. I still await your kestrel.
Istredd of Aedd Gynvael

Let us begin, dear reader, with a riddle. What links a town like Vizima the proud capital of Temeria, or Oxenfurt, a center of learning for all the North, with Aedd Gynvael, a provincial settlement at the end of the know world? Nothing, it would seem... After all, each of these places looks, sounds and even smells different. Their origins, however, are identical — all were founded atop ancient elven cities. The ruins sprawling beneath their streets bear witnesss^[sic] to this fact.
A tour of elven monuments is best begun in Vizima - in the city sewers, to be precise. A dangerous place, to be sure, so it is worth bringing along a well-armed guide. A branch of the sewers leads to the remains of an Aen Seidhe city. One can still admire its masterfully carved plafonds, peer into its immaculately polished marble facings, find artifacts discarded by the Elder Race and hold ancient tomes that disintegrate in one's hands. Equally impressive monuments of elven culture can be found only in Oxenfurt — as well as somewhere in the wilds of Velen, though I have been unable to verify this information personally.
What caused elven civilization to collapes? Plague? Cataclysm? No, dear reader. Their destruction was caused by us, by humans. We drove the elves from their cities and, instead of occupying their marvelous palaces, we dismantled them to build our meager and crooked huts. All that remains is that which we covered in debris and sludge, and then wiped from our memories for centuries.