High Horn Keep, part of my own world of Luma
I have a number of story worlds that I build on at times. Luma is one of the longer running ones, and has a number of maps that people are familiar with; Bourmout, Haerlech, Sagemound, among them. Those are mostly over in one part of Luma. This explores some areas further away. The lower level was a bit of an after thought, thus why it utilizes the previous above ground perspective view.
The backstory info might be too long for artstation so you can check that out on tumblr, DA, or patreon.
https://www.imaginebetterworlds.com/mylinks