- The Second Empire made some advances into the periphery of Black Marsh, but they didn't stay long. Arx Corinium, once an Imperial fort, is now occupied by denizens of the deep swamp—and even stranger things.
Arx Corinium is a group dungeon found in western Shadowfen. While previously constructed and held by the Imperials, the fort has fallen into disrepair and is overrun with Lamias. A group of nereids now occupy the flooded fort and focus on restoring balance to the land. Rumors say the fort is home to a great source of power, although it is perverse, corrupted.
- Arx Corinium Objective: Explore the ruins of the Imperial fort Arx Corinium.
- Arx Corinium Pledge: Explore Arx Corinium and return Undaunted.
There is one Achievement associated with this dungeon:
- Before dungeon scaling was introduced in Update 5, Arx Corinium was designed for 28–31.