User blog comment:Kacj321/Entire Tamriel Landmass built into Skyrim/@comment-3428817-20111128072831

I'd have to agree that these locations may be part of future DLC's. The same thing was done in Fallout New Vegas. Places such as the Northern Passage, Canyon Wreckage, and the Abandoned Brotherhood Of Steel Bunker were not accessible or couldn't be interacted with. Later, they became DLC access points for Honest Hearts, Lonesome Road, and Dead Money. We'll just have to wait and see.