https://www.gamespot.com/articles/assassins-creed-origins-heres-how-to-find-papyrus-/1100-6454582/

Assassin's Creed: Origins is out now on PlayStation 4, Xbox One, and PC. One element of the game is legendary and rare gear, which of course is not so easy to find. One way to do this is to locate papyrus scrolls throughout the world; they include a hint for where to find buried treasured, which comes with a rare or legendary item, along with 500 XP.