Follow the corridor down into a room with a dog statue in the center. Exit the room and you will see some urns before you. Smash them to get a passage to a room with a hole in the middle. Down there is the Stele. But I take the other way around to first collect all the treasure.
So I leave the urn slide passage and go left down the hall.
You will get to another storage room with some more urns to smash for a slide passage.
If you're the "I don't care about treasure I just want the stele" kind of person: push down the shelf before you go down the hole. Makes it easier to get up again...