Originally these walls immune to most attacks, but could be damaged with health bolt rings (Ravens Fury).
In the ?? update these walls were changed to be immune to ALL attacks and can no longer be destroyed. Also, where before they spawned in fixed locations, they now spawn randomly which means some routes to the bottom of the dungeon will become impassable and you must take a different path (or you can also log out by the stone wall for at least 5 minutes so the dungeon will reset and there is a chance it will be replaced with a killable ice wall, though it can spawn a stone wall again).
