Skyrim Contains Most Of Tamriel, Sort Of

As noted in this post (via here), Skyrim contains much of the rest of the continent of Tamriel in rudimentary form outside its mountains. bBorderRegionsEnabled=0 in Skyrim.ini and no-clip on does the trick. Thanks, commenters. There's a huge heightmap out there, well beyond view distance, down into Morrowind, Cyrodiil, and Hammerfall. It's a bit buggy, mind and seems unstable once you're out of skyrim. Looks like it's just a chunk of the world rendered around Skyrim for view-distance authenticity, rather than any possible expansion.