So, here I'm trying to do massing on the internal structure of the castle. I beefed up the walls, as I assume masonry buildings of that era were at least 10 feet thick for the exterior walls. The grey is a refined sketch of the massing, the red was the original mass. The shaft to the SouthEast is going to lead down to an alchemical lab or something, the western half of the fortress is the "inner keep" with a well and an secret exit down to the river.

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