Storage Cavern beneath Luthadel

Storage Cavern beneath Luthadel appears in Mistborn.

The Storage Cavern beneath Luthadel is a hidden subterranean complex constructed by the Lord Ruler as a final contingency against the impending doom of the Deepness. Though its existence is only confirmed in The Hero of Ages, its purpose and contents are foreshadowed across the earlier books through references to the Lord Ruler’s secret caches and the mysterious disappearance of his most valuable resources. In the final book, the cavern becomes the focal point of the protagonists’ desperate search for the atium cache and the key to defeating Ruin, transforming from a mere rumor into the literal and symbolic heart of the series’ climax.