The mine/cave outside of Chorrol, Hidden Passage, but how... Options

[liquidneon]

Has anyone else cleared the mine just south/east of the entrance to Chorral, just a few hundred feet to the left as you exit the city?

At the end of the cave, there is a wall with a crack through it, through which you can see another room that looks to be inside of a castle with different walls and floor from the cave.

The portion of the wall with the crack is discolored like it can be blown open, but I have had no success bashing, shooting or in any other way damaging the wall to get through. There is a lone torch stuck in the ground near the wall. This is in the last room of the cave that has a few tents and bed rolls next to a camp fire.

Has anyone else found a way through? Maybe I don't have enough strength yet to bash through it?