The Magmadome

From publisher blurb: Purple Mountain IV: The Magmadome is a Pathfinder Roleplaying Game compatible module designed for four 4th-level characters that uses the medium XP advancement track. Play it in any campaign setting with a mountain-based megadungeon, or as a stand-alone dungeon with a mega-dungeon feel. Things are about to get hotter for the players characters when they stumble into the middle of a magma-fuelled contest of elemental dominance. Many enter the magmadome, only one will leave.