Tevinter almost made it to a Dragon Age game once but the fourth instalment now seems to be set in the area, lacking only the official announcement from EA and BioWare.
One of the regions in the world of Thedas that we haven't visited yet but heard a lot about is Tevinter - the land where magic goes practically unchecked and mages hailing from the area are often condescending and arrogant, with the rare exceptions that turn out to be nice and helpful.
In case you are not that much into Dragon Age lore and need more context, it's also the place where slavery is legal and even encouraged since it carries prestige in certain situations.
BioWare originally intended to release a smaller, narrative-driven game that was supposed to be located in this blood magic infested land but the resources were eventually allocated to Mass Effect Andromeda and Anthem. Quite the headscratcher in hindsight. Anyway, the development on the game eventually resumed but it was shifted to a major project, not unlike Inquisition, as opposed to a smaller title.
There were hints that Tevinter Imperium would be where the events of this game would play out but there was never an official confirmation. Even today, neither EA nor BioWare explicitly stated it would be the location of DA4 but BioWare: Stories and Secrets from 25 Years of Game Development leaves little to no doubt.
The page you can see in the image embedded into the tweet above states we are going to Tevinter and explicitly says Dragon Age: Morrison will take us there since the events of Inquisition and its DLC, Tresspaser, threaten Thedas once again.
DA: Morrison is the codename for Dragon Age 4 and was initially called DA: Joplin, before Anthem and Andromeda started giving it development troubles.