The Elder Scrolls 6 is in Hammerfell (Maybe)
After way too many hours of digging through the depths of the internet and the various threads of speculation posted on reddit, twitter, the ESO forums, and everything in between, I can say with so much certainty that the Elder Scrolls VI will be set in Hammerfell, the Iliac Bay region, and potentially including the entirety of High Rock as well.
How can I be so certain you may ask? Well, buried in a reddit thread on r/teslore is user u/Vicktoracri’s analysis of the intro trailer with some fairly convincing map analysis accompanying it. While originally I had thought that the body of water in the teaser was not Iliac Bay as you’d be able to see a landmass (High Rock) across the way, after analyzing the photo and maps multiple times, it’s entirely possible that the camera angle is set in the perfect position to not show any landmass on the right (but trust me that landmass would have to be right out of shot). By not showing a landmass in the teaser, Bethesda is allowing us to go on this wild goose chase. Had they shown land, then I feel that most folks would be able to figure out and agree upon the fact that this is indeed Hammerfell.
Now what about that castle in the foreground? Do we have any idea what it is? There are a lot of theories on the internet and to be frank, I don’t really believe we have enough information to figure it out. What we can observe, however, is that the castle is in a ruined state and it does sit atop a large crater-like geographical feature. There’s a theory that I’ve seen mentioned in a few of the nerdier Elder Scrolls discussion locales (of which I frequent) stating that that crater is potentially the mythic impact site of Volendrung, a hammer forged by the Dwemer accompanied by the tale that “Legend states that the chieftain [of the Rourken] threw his hammer across Tamriel and proclaimed that his clan would settle wherever it landed. The hammer landed in the province of Hammerfell (hence the name).” The only problem with this theory is that the Rourken supposedly built their capital city there, which was then swallowed up by the desert. There’s no desert in view here, and so perhaps that crater is something else.
The last piece of evidence we have to consider is the city in the distance, which very much looks like it lays atop a river delta. There are cities in Hammerfell that lie on the shore, in which case this city would have to be Lainlyn or Satakalaam. If we are actually looking at the north shore of High Rock, then there are a few options for what city this could be.
So, while I think the internet is tending towards High Rock, I do believe there’s some good evidence for Hammerfell that should not be discounted. I also think it’s entirely possible that the game would include both, which may be an insanely huge game but as we know, Fallout 76 is four times the size of Fallout 4, so it's not out of the realm of possiblity.