Risen Barred cave/mine in northwest

After doing all the hard work wading through skeles near the northwest castle, I headed on down the path to toward the beach. But just as you leave the castle area their is a cave/mine blocked by a portcullis/bars.(A short distance from the bed as you leave the castle ruins.) Telekinesis doesn't do anything, and I've yet to find another cave/mine that exits there. Spoil me a lil please

It's part of the main quest.

That location is very atmospheric on the cliff top. What a great game.