This castle is abandoned in our world. It served as a test structure while adding to our view from the main mountain base. I tried to make it seem like the castle was part of the mountain by extending it's towers down the side. You access the castle by going under the mountain and up a laddered tunnel. You pop out on the castle's balcony looking directly through the main door at the tree.

A balcony on the back overlooks uncharted territory.