My favorite aspect of the castle was the mines and counter-mines. Back in the day, some people were trying to break in to the castle and kill the inhabitants by digging a mine. Those inside heard of the plan and began digging a counter-mine to render the invaders' mine useless.
You can go into these mines, but there is a big sign warning, "Enter at your own risk." I see why. The ceilings are only about three feet tall so you have to bend double to travel them. I only made it a few hundred feet before I got claustrophobic and got out.
Back outside, I read that the insiders won, but with little time to spare. You could tell their desperation because their mine was all twisty and small as opposed to the invaders' deep, straight mine.

