Halls of Giants (2005)

From the Introduction:

An ancient ruined keep, surrounded by a stream of water, stands before the entrance of the Halls of Giants. This oversized underground complex goes deep in the belly of the earth. The first level belongs mainly to guards and warriors but features a temple area too. Going deeper to level two, the chieftains’ rooms are found. On the third level, a mining complex surrounds a great rift. A great staircase has been built over the rift at this level. The fourth level is under construction, dug all around the great rift.
You can place this dungeon just about anywhere. It could be inhabited by many kinds of giants, mainly those who dwell in rocky areas. The entrance could be on top of a mountain, on a rocky hill or in plain ground.
Some hints to use the Halls of Giants follow:

• An evil fire giant cleric has discovered that an ancient artifact once believed destroyed in a underground volcano is still intact and has begun to kidnap and enslave the neighbor people to dig the mountain.
• An ancient demon of the past has been freed from is slumber by stone giants who dug too deep in the earth. A group of good-aligned characters managed to seal the Hall of Giants but the demon lure the PCs to his lair through the stone giants now enslaved.
• An evil necromancer turned all of the inhabitants of the Halls of Giants into undeads under his control. The undeads plague the nearby territory gaining fresh corpses for the necromancer’s evil experiments.
• A duergar tribe has occupied the Halls Of Giants, searching for gold ore in its deeps. The duergar use illusions in order to make the people believe the giants are still there.