Abandoned Mine
From Drunkapedia
The Abandoned Mine, located just NW of Arwic, is also known as Subway, Sub, or Hub, depending on which server you play on. It is one of several Portal Nexus Dungeons.
To get to the bottom, cross the room to the passage accross from the exit portal, and wind your way down the spiral counter clockwise.
At the bottom of the dungeon are portals to the following locations:
Qalaba'r, Mayoi, Hebian-To, Shoushi, Cragstone, Arwic, Holtburg, Glenden Wood, Rithwic, Zaikhal, Samsur, the Underground City, and Yaraq.
The Surface portal exit is just NW of Arwic.