The beautiful cross-section above immediately brings to mind Skull Mountain. It's from The Secret of Forsaken Peak, a forthcoming 5E D&D Adventure that I heard about today. The creators are Dave Hamrick and Justin David Russell (who does the cartography).
You can read more about it here:
The Secret of Forsaken Peak is a dark fantasy/horror adventure for characters of level 5-15 using Fifth Edition rules. In addition to the 30+ map adventure offering over 750 areas, chambers, and other places of interest, the book boasts over 100 new original monsters, more than 30 new magic items, new player options introducing subclasses, feats, and backgrounds, full-color illustrations and a whole lot more.
The first part of the adventure, Goblin Mine, will be part of the first issue of a magazine Broadsword that the authors are kickstarting right now.
Last Updated: 1/2/2018 What is the Secret of Forsaken Peak? A shadow falls across The Graywood Forest, cast by the titanic, lonely mountain known as The Forsaken Peak. Its jagged, snow-capped peaks hide many secrets and equally as many terrors. For years, the mountain has been at the heart of multiple mysteries.