- Main article: Books (Online)
- Location: Near the entrance to Fort Sphinxmoth, Reaper's March
- Author: Calantius of Skingrad
- Collection: The World and Its Creatures
The ruins of Fort Sphinxmoth lie hidden in the canyons of northern Elsweyr, near the border with Valenwood. The Reman Empire built this fortress into the side of a mountain so as to have an impregnable base, from whence columns of Legionnaires could be sent out to patrol the borders. The location offered elevation and good source of stone to build the walls of the outside fortress. The result was a large bastion with defensive walls, towers, and a subterranean series of halls, rooms, and dungeons built into the bowels of the mountain. It is said that the Legionnaires outfitted their fortress with many traps of cunning and clever design, to defend themselves should the walls ever be breached.
Fort Sphinxmoth was abandoned by the Legions after the fall of the Second Empire, then was traded back and forth for a generation between warring Bosmeri and Khajiiti tribes, suffering additional damage every time it changed hands. Finally a landslide destroyed much of the upper works, and the fort was vacated by both sides. Word of mouth says that nothing worth looting was left in Fort Sphinxmoth, and today it's no more than an overgrown ruin that's been bypassed by history.