D&D 5E: Numenera: Arcana of the Ancients: Where Machines Wait

They call it the Grave of the Machines. An underground mausoleum of the ancients, filled with their wondrous devices and strange magic. Those bold enough to venture into its depths (and return) spin tales of sights and encounters so astonishing they could not possibly be boasts or mere fiction. And they say its riches are as vast and unfathomable as its depths.

Venture into the Grave of the Machines, if you dare, for adventure unlike any you’ll find in typical ruins or dungeons. Where the Machines Wait is a mega-adventure for 5e for characters of roughly 5th level. It can be played as a series of short ventures into the Grave of the Machines, easily placed between other adventures in your campaign. Its deeper plotline can be introduced at any time—or it can remain in the background as you simply crawl the dungeons.