As you know, there are hidden walls in Elden Ring, but one particular wall takes some work to knock down.
Discovered by reddit user teristam, there is a wall over in Volcano Manor that will only come down if hit 50 times.
Once the wall disappears, you will find Rya and Knight Bernhal's room, which is a bit odd considering you can find it easily enough and walk into it the normal way. Why breaking down a wall to get into the room is an option is not known, as there really is no point to it, unless you really want to smack something 50 times instead of going about it in the normal manner.
I dunno if this is the same wall or not, but it appears if you want to make things go a bit faster when tearing down the wall, or any wall for that matter, reddit user daxramas has a solution.
It's possible there are other walls in the game that act in this manner, some, like this one, will reappear after you take a rest.
Anyway, if you want to try this out for yourself, just head over to Volcano Manor. And start smacking the hell out of other walls in the game just for fun. You never know what could be behind them.