Location from The Kingkiller Chronicle by Patrick Rothfuss
A sprawling maze of tunnels, abandoned rooms, and ancient pipe systems beneath the University. Home to Auri, who has named every passage and made the darkness her own.
The Underthing is older than the University above it, which is itself older than anyone remembers. Down here, the boundaries between engineering and mystery dissolve. Pipes carry heat and water through passages that follow no logical plan. Rooms open into other rooms that shouldn't exist. Auri moves through this darkness like she belongs to it, naming each space — Cricklet, Billows, Mantle, Wains — as though naming were a form of love. She has made a home in a place most people would call a tomb. Kvothe is one of the few who knows the way to her door, and even he has only seen a fraction of what lies below. There are things in the deep Underthing that even Auri avoids.
A warren of stone corridors, dripping pipes, vaulted chambers, and forgotten rooms lit only by cracks of light from above or the occasional sygaldric lamp still glowing after centuries. Some passages are tight as crawlspaces; others open into cathedral-sized vaults where water echoes endlessly.
Also known as: the Underthing, beneath the University, the tunnels