Charos' tomb is located underneath McGrubor's Wood and is first seen during the You Are It quest. It can be accessed through a mysterious hole in the wood dug up during the quest.
The tomb features a small passageway leading to an open room with Charos' coffin and decorative scenery like archways and a mantle that houses several jade statues. During You Are It, players have to break the stone jade statue on the mantle by interacting with it. The coffin can be searched for Charos's Journal.