From Diablo Wiki
The Pandemonium Fortress is the town area of Act Four. It's an austere town hewn from stone and perched atop a long, winding stairway down into the plains of Hell. There are only two NPC merchants in Act Four and neither of them are much for conversation, and the town is more of an outpost, with only one small area to explore.
This category lists all the npcs, quests, and other items of interest connected with or found in the Pandemonium Fortress.