The Walls of Night were the outer boundry or Arda when it was flat in both the First Age and Second Age, the utterly black mountain bounds which encircled Ambar prior to its reformation in Second Age 3319. These walls marked the edge of the world, they encircled Ekkaia and the only exit was the Doors of Night in the farthest West. The Gates of Morning in the farthest east served as the only entrance.
Places of Note:
- Neversleeping Guard
- Foster, Robert. The Complete Guide to Middle-earth.