Question: Shouldn't opening the Palace of Eternity (pulling out of the stone heads and falling in the place) only have to be done once (Oxley mentions he was there before)? Because who's gonna fill all that sand back up and replace all the stones that keep the sand in?
Answer: Oxley had been there before but couldn't figure out how to get in, so the stones were never removed by him.
That is true, but... There are dead adventurers inside... And this place is a LOT harder to reset than e.g. the one with the golden idol.
Spiny Norman