The Iron Arch is a place inside of Sorrow's Furnace. It is a dark cave southeast of Sorrow's Belly that features one of the entrances into the Forge with three Furnace Guardians guarding it.
The following quests take place in the Iron Arch:
- Fire in the Hole: It is the location of the Flame Djinn.
- Summit Slaves: It is one of five places that must be scouted.
- Tasca's Reprise: It is the location of the group that has Tasca's Map.
Makar Thoughtslayer can always be found underneath the stone bridge in Iron Arch.