This will be a text walk through i meant to have a video for it but somethings happened to my PC.
To start off you must be past chapter 9 or to it so there may be spoilers be aware.
You start in Sanctuary Hole, Work your way down till you reach Caustic Caverns,
There will be a transition and a fast travel point there.
(For Reference this is a good place to grind if your around LVL 18)
There will be a bulkhead to the right of you when you enter the fast travel spot, or straight ahead if you enter from top side.
A wheel to the left of the door will open it, at this point you can run or fight it is a large area and a lot to do down here.
Now run slightly to the left and you'll see a bridge go on it and in to a small tunnel.
After the tunnel proceed ahead following the left wall. There will be an opening soon go straight through it.
You will see a set of black and yellow doors, proceed through, it is a double set so just run past the enemies that spawn.
Stay to the left as you exit there is a corrosive pool to the right.
Head straight and past a house and ammo crates.
There will be a narrow passage stay to the left but keep running, there will be a flat rock jump over the cargo container and turn slightly right.
You will see a minecart track and bridge cross it on the right side.
When you reach the end near the crystals turn right.
and you will see a large flat rock
hop over that and turn left you will now see the Minecraft textured dirt blocks.
Use v to smash them and have fun getting your collectibles. (note you may have to return a few times by saving and quitting to get them all)
Here are some screens after this wall.
Also the gold ore drops cash and the coal drops ammo.
And at last you have this good hunting.
Thanks for reading,