Joerdhgardh Map No. 474 is from the newly-released Joerdhgardh Trails adventure "A Tale of 2 Books." The PCs' journey through the vampire-ruled North Kingdom nears its end as they enter the dungeon beneath Darkhall, the castle of the former dark draug (undead) Thingul. Here the PCs hope to find the evil ice key that they are seeking. The battlemap here shows the 1st (upper) dungeon level.
For more information see the description for Level 1.
This dungeon plan and the variants are released for personal and commercial use under the Open Game License Version 1.0a, which you can read on the Joerdhgardh website at:
www.vintyri.org/joerdhgardh/
Next: Thinguls Escape Route, Station 1