I just killed Baal at lvl28 and in the mine, I found 2 non accessible area.

1) There a gate door on the north eastern end part of the map(cave overall map), where I saw a key outside the door, lying under pieces of broken vases, which I cant pick it up. I try move around but there seems no way I can pick up the key, since no item interaction tab pop out

2) There a hidden room in the south western part of the cave, where I found the room by pressing a hidden switch beside the wall. When I enter the room, there is another button in it, which after I press, a second hidden room with chest will be reveal, but I will get lock in the first room, because the wall/ entrance to the first room will close back once I press the button in first room.

Hope someone can help with the 2 situation above. Thanks

Haha I just found the solutions to solve the problems, so case close. Thanks for those viewing

so whats the trick on the button room?

nm I figured it out too

now if I can just find the dang broken lever for the other room!

The lever handle found in the SW section fits a broken lever socket in the NE section. The fixed lever opens a secret room in the NE section next to the lever.

after fliping swith go back to secret button on wall, both chests are locked btw