you have the brick-breaking sword, climb over the top of the pyramid and enter the sphinx. break the walls and fall down to the treasure room. each chest have like 8 items and you can open one chest each time you enter the room. just enter and exit, jumping over chests until you reach the last. i think that's the one that has stones in it.
there's also a trick wall near the end of the pyramid dungeon (if you jump over the final pit). and a trick ceiling above that same pit. i forget just what their treasures are, but there might have been a potion or two.
the reason for 