|Description||Slime-choked immense sewer and cavern network|
- they run under numerous other Abyssal Realms;
- they contain a maze of tunnels and caverns;
- they are connected to a river, in this case the River Styx;
- they are filled with detritus and slime.
Other brave creatures use the Undersump as a covert conduit between Abyssal Realms, but need to take care Jubilex does not catch them in the act. Being caught, however, is made less likely by Jubilex's inherent indolence and lack of care of his realm, indeed, parts of his realm are now claimed by others.