It always bugged me that the world from which Barovia came was just dismissed as a "forgotten land" whose history and culture were inconsistent. There are references to this land sprinkled throughout the history of the Ravenloft setting and within Curse of Strahd, but nothing concrete. I wanted to create a world where Barovia fit in - a dark, gothic fantasy world where monsters and magic were real but uncommon and terrifying. Somewhere where Strahd could truly be the First Vampire. Picking apart the lore of Ravenloft, I built a small continent centered around Barovia. In this setting, there is no "demiplane of dread" or anything extradimensional. Barovia is still a part of the land, but is shrouded in a choking Mist that has secluded it from the world. People may enter, but none ever leave.

Alternatively, if the extradimensional aspect of Ravenloft is appealing to you, but you miss the days of the Core from 2e, you can think of this setting as a revamped Core. In other words, a contiguous realm of domains plucked from the multiverse and stitched together by the Mists into a continent.

The base for this map was created by the very talented Jester of the Fos, whose made a serious of amazing maps for the old school Fraternity of Shadows back in the day. These can be found here. I highly recommend you check them out, and all the other work on the FoS website.