The Library of Babel is the library district of Dis. While the library contains every book written, few access it due to the infamous beings known only as librarians. Indeed, the word alone sends a shudder down the spine or spinal analogue of many Disians.

The structure itself is a many-tiered, spiral tower with an exterior of sandstone blocks. The interior is devoted to huge, vaulted chambers with every surface convered in shelves. Some shelves are several stories above the nearest floor, possibly due to the fact that the librarians have little need for ladders or stairs, as they are expert climbers. Still, long precarious ladders are scattered around the interior, and magical levitating elevators provide access to the highest reaches of the tower.

Outside the tower, walls and ramparts were long ago built by residents of Dis, creating the distinctive Reverse Fortress, meant to contain the librarians. The Library Guard is a motley and paranoid group. They have little sympathy for those who would like to access the library, and while they are quite willing to allow entry, they greet those leaving the library with suspicion, fearing a trick or intrigue by the librarians.