The Nordia Tunnels is a mining network that spans underneath the Greydall Mountains. It was abandoned because of the Overrun of Monsters. The Tunnel had rich deposites of minerals that fueled Balandor's Riches. It's doors and keys are very old and withered because of hoe long human have left.
Find the Nordia Tunnel key in a Chest in the West section of the tunnels. Then use the Key to access the East side to follow the tunnels out.
Svlyian Savage Troll